WASHINGTON (AP) — If all goes smoothly, the American people will choose a new president on Tuesday, the Electoral College will affirm the election next month and either Democrat Hillary Clinton or Republican Donald Trump will take the oath of office on Jan. 20.
But why assume everything will go smoothly in an election year that already has seen more than its share of surprises. What, for example, if some electors refuse to vote for the candidate who won their state? What if the winner is sitting in a courtroom instead of parading in Washington?
The FBI is investigating newly discovered emails that might be related to the dormant probe into Clinton's use of a private email server. The future of that investigation is uncertain, and there could be developments after the election.
On the Republican side, Trump faces unresolved cases in New York and California related to Trump University, as well as numerous other civil suits. He also has threatened to sue The New York Times over its publication of details regarding his taxes.
Electors who go rogue — called faithless electors — are rare and have never changed the result of an election.
A look at the process:
In the presidential contest, Election Day voters are casting ballots for their state's electors, who are in turn expected to cast votes for the presidential candidate who wins the most votes in their state. According to the National Archives, 99 percent of electors through U.S. history have voted for the candidate who won their state.
Electors are chosen by each party, and typically are party insiders who can be trusted to vote for their candidate. But in many states, they aren't legally required to support that person.
STATE LAWS VARY
Twenty-one states don't require their electors to go along with the popular vote, according to the National Conference of State Legislatures. The 29 states that require faithfulness from their electors can impose a variety of punishments, including fines.
One elector has already said he won't vote for Clinton, despite a fine. Robert Satiacum, a member of Washington's Puyallup Tribe, says he believes Clinton is a "criminal" who doesn't care enough about American Indians and "she's done nothing but flip back and forth."
Satiacum faces a $1,000 fine in Washington if he doesn't vote for Clinton, but he said he doesn't care.
"She will not get my vote, period," he told The Associated Press.
Oklahoma also imposes a fine, according to NCSL. In South Carolina, a faithless elector is subject to criminal penalties.
"Apart from the state laws that attempt to corral electors, the theory is that the electors can vote for anyone who is qualified to be president of the United States," says constitutional law scholar Robert Bennett, an emeritus professor at Northwestern University's Pritzker School of Law.
KICKING IT TO CONGRESS
There are 538 electors, and the winner must receive half of that plus one, or 270 electoral votes. If electors split votes for some reason and no candidate received 270, the decision is kicked to the House of Representatives.
Each state's House delegation has one vote, and must pick from the top three candidates who received the most electoral votes. The Senate decides the vice presidential contest.
Congress' role makes it less likely that Democrats, in particular, would split the electoral vote, says John Hudak, a fellow in governance studies at the Brookings Institution. That's because there are more Republican states than Democratic states, so a House vote would almost certainly produce a Republican president.
"There is no incentive for any Democratic elector to vote for anyone else but Hillary Clinton," Hudak says.
Even if there were any damaging developments in the review of the newly discovered emails, the content of which is still unknown, Clinton would still be able to assume the presidency if she wins and the Electoral College affirms the results.
If either Trump or Clinton were to die after the election and before the Electoral College votes, their electors would be free to vote for someone else. This happened in 1872, when Horace Greeley died after losing the election to Ulysses S. Grant and before the electors met. But it didn't matter because Grant had swept the election.
IT'S A LONG SHOT
Faithless electors are extremely rare, and the system has generally held up as intended. On four occasions, a candidate has won the popular vote and lost the electoral vote, including the 2000 race that Republican George W. Bush eventually won over Vice President Al Gore. Never has a faithless elector changed an election result, and there have only been a handful of them in the past 50 years. There hasn't been an electoral tie in more than 150 years.
"We have not had to face some of these unusual contingencies," like a mass of electors defecting, says Thomas Neale, an Electoral College expert who is also an elections analyst for the Library of Congress. "There's a very high percentage of success."
Associated Press writers Alan Fram in Washington and Meg Kinnard in Columbia, South Carolina, contributed to this report.