Explainer: Everything you need to know as Americans go to vote

The US presidential election takes place on Tuesday. But it's possible the candidate with the most votes from the public won't be the winner.

In the United States, the winner of a presidential election is determined not by a national vote but through a system called the Electoral College, which allots “electoral votes” to all 50 states and the District of Columbia based on their population.

Complicating things further, a web of laws and constitutional provisions kick in to resolve particularly close elections.

Here are some of the rules that could decide the November 3 contest between President Donald Trump and his Democratic challenger Joe Biden.

How does the Electoral College work?

There are 538 electoral votes, meaning 270 are needed to win the election. In 2016, President Donald Trump lost the national popular vote to Hillary Clinton but secured 304 electoral votes to her 227.

Technically, Americans cast votes for electors, not the candidates themselves. Electors are typically party loyalists who pledge to support the candidate who gets the most votes in their state. Each elector represents one vote in the Electoral College.

The Electoral College was a compromise between the nation’s founders, who fiercely debated whether the president should be picked by Congress or through a popular vote.

All but two states use a winner-take-all approach: The candidate that wins the most votes in that state gets all of its electoral votes. Maine and Nebraska use a more complex district-based allocation system that could result in their combined nine electoral votes being split between Trump and Biden.

Can electors go rogue?

Yes.

In 2016, seven of the 538 electors cast ballots for someone other than their state’s popular vote winner, an unusually high number.

Thirty-two states and the District of Columbia have laws intended to control rogue electors, or “faithless electors.” Some provide a financial penalty for a rogue vote, while others call for the vote to be cancelled and the elector replaced.

When do the electors’ votes have to be certified by?

Federal law requires that electors meet in their respective states and formally send their vote to Congress on “the first Monday after the second Wednesday in December.” This year that date is Dec. 14.

Under US law, Congress will generally consider a state’s result to be “conclusive” if it is finalised six days before the electors meet. This date, known as the “safe harbour” deadline, falls on Dec. 8 this year.

Those votes are officially tallied by Congress three weeks later and the president is sworn in on Jan. 20.

What if officials in a particular state can’t agree on who won?

Typically, governors certify the results in their respective states and share the information with Congress. But it is possible for “duelling slates of electors,” in which the governor and legislature in a closely contested state could submit two different election results.

The risk of this happening is heightened in states where the legislature is controlled by a different party than the governor. Several battleground states, including Michigan, Pennsylvania and Wisconsin, have Democratic governors and Republican-controlled legislatures.

According to legal experts, it is unclear in this scenario whether Congress should accept the governor’s electoral slate or not count the state’s electoral votes at all.

What if a candidate doesn’t get 270 votes?

One flaw of the electoral college system is that it could produce a 269-269 tie. If that occurs, a newly elected House of Representatives would decide the fate of the presidency on Jan. 6, with each state’s votes determined by a delegation, as required by the 12th Amendment of the US Constitution.

Currently, Republicans control 26 state delegations, while Democrats control 22. Pennsylvania is tied between Democratic and Republican members. Michigan has seven Democrats, six Republicans and one independent.

The composition of the House will change on Nov. 3, when all 435 House seats are up for grabs.

Will the system ever change?

Critics say the Electoral College thwarts the will of the people. Calls for abolishing the system increased after George W. Bush won the 2000 election despite losing the popular vote, and again in 2016 when Trump pulled off a similar victory.

The Electoral College is mandated in the Constitution, so abolishing it would require a constitutional amendment. Such amendments require two-thirds approval from both the House and Senate and ratification by the states, or a constitutional convention called by two-thirds of state legislatures.

Republicans, who benefited from the Electoral College in the 2000 and 2016 elections, are unlikely to back such an amendment.

Individuals states do have some freedom to change how their electors are chosen, and experts have floated proposals for reforming the system without a constitutional amendment.

Under one proposal, states would form a compact and agree to award all their electoral votes to whichever candidate wins the nationwide popular vote.

What time do polls open and close?

The opening and closing times for polling stations vary from state to state, in some cases by city or county.

Some states allow people waiting in the queue when the polling station closes to cast their vote – some do not.

Most polls open at 6am and the latest they stay open is until 9pm (in New York and North Dakota).

In Vermont, early-risers can cast their vote at 5am.

All polling stations will close by 9pm ET on November 3 (2am UK time on November 4).

Who can become president?

The President of the United States can be a man or a woman of any race or any religion, but they must:

• be at least 35 years old
• have been born in the US
• have lived in the US for at least 14 years

The rules also state that one person can be in the job for a maximum of two terms. (The only exception to this was Franklin D Roosevelt, who was elected for a special third term at the height of World War Two.)

These states could decide the result

The US presidential election will be decided by about a dozen states that could swing for either President Donald Trump, a Republican, or Democratic challenger Joe Biden.

These states will play a critical role in delivering the 270 electoral college votes needed to win the White House. Due to a surge in mail voting amid the coronavirus pandemic - as well the states’ varying rules for when ballots can be counted - the results may not be known on Election Day, Nov. 3.

Florida

Electoral votes: 29

Polls close: 7pm ET (Several counties in northwestern Florida are an hour behind the rest of the state.)

Rating in presidential contest: Toss-up

Other key races: Competitive US House of Representative races in the 15th and 26th districts

Vote counting: Florida has no-excuse absentee voting. Election officials can begin scanning ballots more than three weeks before Election Day, but results cannot be generated until after polls closed. All ballots must be received by the close of polls on Election Day to be counted. However, ballots flagged for signature errors can be corrected until 5pm on Nov. 5.

Georgia

Electoral votes: 16

Polls close: 7pm ET

Rating in presidential contest: Toss-up

Other key races: Both US Senate seats are up for grabs and considered competitive.

Vote counting: Georgia has no-excuse absentee voting. Ballots must be received by clerks by the close of polls on Election Day. Ballots can be opened and scanned upon receipt, but they cannot be tallied until after the polls close on Nov. 3.

New Hampshire

Electoral votes: 4

Polls close: Between 7pm ET and 8pm ET, depending on jurisdiction

Rating in presidential contest: Leans Democratic

Other key races: Governor Chris Sununu, a Republican, looks poised to win re-election.

Vote counting: New Hampshire state officials have said all voters are able to cast an absentee ballot if they have concerns about Covid-19, and the ballots must be received by 5pm on Election Day. Ballots can be pre-processed in some jurisdictions beginning on Oct. 29, but not counted until the polls have closed on Nov. 3.

North Carolina

Electoral votes: 15

Polls close: 7:30pm ET

Rating in presidential contest: Toss-up

Other key races: Competitive governor and US Senate contests

Vote counting: North Carolina has no-excuse absentee voting. Absentee ballots can be scanned weeks in advance, but results cannot be tallied before Election Day. Trump’s campaign has asked the US Supreme Court to block the state’s plan to tally ballots that are postmarked by Nov. 3 and arrive by Nov. 12.

Ohio

Electoral votes: 18

Polls close: 7:30pm ET

Rating in presidential contest: Toss-up

Other key races: Competitive US House contest in the 1st District

Vote counting: Ohio has no-excuse absentee voting. Ballots can be scanned, but not tallied, as early as Oct. 6. Absentee ballots are the first to be counted on election night. Mailed ballots must be postmarked by Nov. 2 and received by 10 days after the Nov. 3 election to be counted.

Michigan

Electoral votes: 16

Polls close: 8pm ET

Rating in presidential contest: Leans Democratic

Other key races: Competitive US Senate contest

Vote counting: Michigan has no-excuse absentee voting. Though there are ongoing legal challenges to change the rules, currently ballots must arrive at clerks’ offices by the close of polls on Election Day. Some densely populated jurisdictions in the state can open and sort absentee ballots beginning on Nov. 2, but the vast majority will not. Clerks can begin scanning and counting absentee ballots at 7am on Nov. 3.

Pennsylvania

Electoral votes: 20

Polls close: 8pm ET

Rating in presidential contest: Leans Democratic

Other key races: Competitive US House contests in the 1st and 10th districts

Vote counting: Pennsylvania has no-excuse absentee voting, and ballot counting can begin at 7am on Election Day. The Pennsylvania Supreme Court ruled on Sept. 17 that officials in the state can accept mail-in ballots three days after the Nov. 3 election, so long as they were postmarked by Election Day.

Texas

Electoral votes: 38

Polls close: 8pm ET (Two western counties in Texas are an hour behind the rest of the state.)

Rating in presidential contest: Leans Republican

Other key races: Competitive US Senate contest

Vote counting: Texas voters must qualify to vote by mail, for example by being older than 65, being ill or disabled, or not being present in their voting county during the early voting period through Election Day. All voters can vote early in-person. The population of a county determines when election officials can pre-process and count mail ballots. If the county has more than 100,000 people, the ballots may be counted after polls close on the last day of in-person early voting in the state, which is Oct. 30. Ballots will still be counted if they are postmarked by Nov. 3 and received by 5pm the day after the election. For military and overseas voters, that deadline is extended through the end of business on Nov. 9.

Wisconsin

Electoral votes: 10

Polls close: 9pm ET

Rating in presidential contest: Leans Democratic

Other key races: No governor or US Senate races on the ballot

Vote counting: Wisconsin has no-excuse absentee voting. Ballots must be received by the close of polls on Election Day, and they cannot be counted until polls open on Nov. 3.

Minnesota

Electoral votes: 10

Polls close: 9pm ET

Rating in presidential contest: Leans Democratic

Other key races: Competitive contests for the US Senate and US House in the 1st and 7th districts

Vote counting: Minnesota has no-excuse absentee voting, and ballots must be pre-processed within five days of receipt. Beginning on Oct. 20, ballots can be opened and logged, but the results are only tabulated after polls close on Election Day. Ballots will be counted so long as they are postmarked by Nov. 3 and received by Nov. 10.

Arizona

Electoral votes: 11

Polls close: 9pm ET

Rating in presidential contest: Leaning Democratic

Other key races: Competitive US Senate contest

Vote counting: Arizona has no-excuse absentee voting. All ballots must arrive by the close of polls on Election Day. Ballots can be scanned and tabulated starting 14 days before Nov. 3 but results not reported until after polls close on Election Day.

Nevada

Electoral votes: 6

Polls close: 10pm ET

Rating in presidential contest: Leans Democratic

Other key races: No governor or US Senate contests on the ballot

Vote counting: Nevada has no-excuse absentee voting, and ballots can be processed upon receipt. Nevada officials will begin scanning and recording ballots 14 days before the election, but results are not released until election night. Ballots postmarked by Nov. 3 will be counted so long as they arrive within seven days after the election.

Iowa

Electoral votes: 6

Polls close: 10pm ET

Rating in presidential contest: Toss-up

Other key races: Competitive US Senate contest

Vote counting: Iowa has no-excuse absentee voting. The ballots must be received by the close of polls on Election Day, or by noon the following Monday if they are postmarked by Nov. 2. Election officials can begin opening ballot envelopes on the Saturday prior to the election and can begin scanning and tabulating them on Nov. 2.

Election calendar: Day by day

US voters will decide whether to give Republican President Donald Trump a second four-year term or replace him with Democratic presidential nominee Joe Biden.

Here are the important dates in the contest:

Nov. 3: Election Day. Due to an expected widespread use of mail-in voting, it is possible a winner will not be known for days as states tally ballots.

Dec. 14: Members of the Electoral College cast their ballots for president. Under the US system, the winner of each state’s popular vote earns that state’s electoral votes, which are apportioned by population. The candidate who receives a majority of the 538 electoral votes available, or 270, wins the presidency.

Jan. 6, 2021: Congress meets at 1pm in Washington to count the electoral votes and declare a winner.

Jan. 20, 2021: Inauguration Day. The winner and his running mate are sworn in as president and vice president at the US Capitol in Washington.

Can Trump call in troops to quell Election Day unrest?

There have been pockets of unrest in battleground states ahead of the showdown between President Donald Trump and his Democratic challenger, Joe Biden, in Tuesday’s election.

On Saturday, peaceful participants at a rally in North Carolina to turn out the vote were pepper-sprayed by law enforcement officials. The Biden campaign cancelled two events after a caravan of vehicles with Trump campaign flags swarmed a bus carrying campaign workers in Texas on Friday.

Trump, who previously declined to commit to a peaceful transfer of power if he decides Tuesday’s election results are fraudulent, could bring in the military or federal agents to quell civil unrest on Election Day.

Here is a look at the laws that give Trump authority in this area, and the limitations on his power.

What is the insurrection act?

Under the US Constitution, governors of US states have primary authority to maintain order within state borders. The 1878 Posse Comitatus Act bars the federal military from participating in domestic law enforcement.

The Insurrection Act, an exception to the Posse Comitatus Act dating back to 1807, permits the president to send in US forces to suppress a domestic insurrection.

The Insurrection Act has been invoked dozens of times in US history, but rarely since the civil rights movement of the 1960s.

It was last invoked in 1992 by President George H.W. Bush when the acquittal of four Los Angeles police officers in the beating of Black motorist Rodney King led to deadly riots. California’s governor supported Bush’s use of the law.

The act gives a president “awesome powers” and should be used as a last resort, said retired Army Major General John Altenburg, now a Washington lawyer.

Did Trump invoke the act in response to this year's anti-racism protests?

Trump considered invoking the act in response to violence and looting at mostly peaceful anti-racism protests in June. Trump dropped the idea after public pushback from Defense Secretary Mark Esper.

Instead, Trump sent the US Department of Homeland Security agents to cities like Washington and Portland, Oregon.

Those agents had military-style equipment but they were civilians and not members of the armed forces.

In the event of unrest on Election Day on Tuesday or in the ensuing days, Trump is more likely to activate those federal agents than the military, said Jimmy Gurulé, a University of Notre Dame law professor and former Justice Department official.

To do so, Trump would need to cite some violation of federal law that the agents are policing against. The DHS agents sent to Portland earlier this year were charged with enforcing a law against vandalizing federal property like courthouses.

Can Trump activate the National Guard

Yes, the US government could activate, or “federalize,” the Army National Guard, a reserve force of part-time soldiers. Those civilian soldiers are usually activated by governors, but federal law also allows the US government to mobilize them.

Once federalized, National Guard soldiers are under the full command and control of the defence secretary until they are returned to state status.

This year, many state governors have activated the National Guard to respond to the coronavirus pandemic and support local law enforcement in quelling disturbances.

So trump need not have a Governor's approval for sending in troops?

Right. Under the Insurrection Act, if a president determines that a rebellion has made it “impracticable” to enforce US law through ordinary judicial proceedings, he may activate the armed forces without a governor’s approval “to enforce those laws or to suppress the rebellion.”

Historically, presidents and governors have generally agreed on the need for troops.

Trump can activate DHS agents, who are federal government employees, or the National Guard, without state approval.

There are limits, however, on the president’s power. Federal law makes it illegal for the military or other federal agents to interfere with an election. Deploying the military or DHS to polling places is illegal, for example.

Can a court block a president's use of force?

Yes, but courts have historically been reluctant to second-guess a president’s military declarations, said Robert Chesney, a law professor at the University of Texas.

“When a president claims that the facts on the ground warrant invocation of the Insurrection Act, courts ordinarily would not second-guess this,” Chesney said. Judges, however, could break with precedent if they believed Trump had relied on false claims to justify the use of force, he said.

If Trump sends in DHS or other federal agents, they must respect the constitutional rights of civilians. Advocacy groups like the American Civil Liberties Union accused the agents in Portland of making arrests that violated the constitutional rights of protesters and journalists.

But the Trump administration had the lawful authority to use the agents, legal experts said.

WITH ADDITIONAL INPUT FROM THE GUARDIAN AND BBC