The electors will gather at their state capitols on Monday and vote to formally make Donald Trump the 45th president.
Tens of thousands took to the streets in the weeks after the election, outraged that Trump is the new president-elect.
Over 4.9 million people signed a petition to encourage the Electoral College to make Hillary Clinton president instead, partly because she won the popular vote.
With so many citizens calling on the Electoral College to choose Clinton, and some electors even saying they will switch their votes, could it happen?
Trump won the popular vote in 30 states and one of Maine's districts — which, along with Nebraska, splits up its electors by district — giving him 306 electoral votes.
While Clinton won over 1.3 million more votes than he did overall because she carried population-heavy states like California and New York, she won the popular vote in only 20 states plus DC, giving her 232 electoral votes.
Members of the Electoral College who decide to go against their state laws or party rules telling them who to vote for are quite ominously called "faithless electors."
They're pretty rare in modern political history. Thomas Neale, an expert in American government and the Electoral College for the Congressional Research Service, found that only eight electors have been faithless since 1900.
Only electors from the party that won the popular vote in the state get to cast their ballots on Monday, so only Republican electors will vote in the states that Trump won, and only Democratic electors in the states Clinton carried.
That means Clinton would need 38 electors to vote for her instead. As Neale told Business Insider in November, "that would require a lot of electors to change their mind."
Several barriers are in place preventing electors from turning "faithless."
First, Neale said, 30 states plus DC have laws on the books "binding" their electors to vote for the candidate who won the state's popular vote. Punishments for becoming a faithless elector range from paying a fine to being replaced with an elector who will follow the rules.
Trump has 155 unbound electoral votes, so there are technically enough electors who could decide to vote for Clinton and wouldn't get punished legally for it.
Second, electors are usually selected by the political parties in each state, Neale said. Because 306 electors voting on Monday will be Republicans, the petitioners encouraging them to vote for Clinton instead would have to convince them to abandon their party.
"The important point here to realize is these are all party loyalists, and they are pretty carefully vetted," Neale said. "Part of that is because there have been the occasional faithless electors in the past who have been an embarrassment to the party, and they want to make sure they avoid it."
The Associated Press interviewed over 330 electors, and while they expressed widespread discontent with the electoral process, they said they don't intend to derail Trump's presidency.
A few electors have spoken out about voting for someone other than Trump, including Christopher Suprun from Texas. (The state doesn't have a law to punish faithless electors.)
"I am asked to cast a vote on Dec. 19 for someone who shows daily he is not qualified for the office," he wrote in a New York Times column published December 5. "The election of the next president is not yet a done deal. Electors of conscience can still do the right thing for the good of the country."
But unfortunately for Clinton, Suprun and other faithless electors — some saying it's "moral" — have said they plan to write in the name of Ohio Gov. John Kasich, former Republican presidential candidate Mitt Romney, or Sen. Bernie Sanders. For his part, Kasich released a statement on December 6 urging electors not to vote for him.
Even if electors turn faithless, members of Congress can formally protest elector votes, and have them thrown out, when they officially count the ballots in a joint session on January 6.
"One of my legal colleagues suggests that the joint session is the 'break glass in case of emergency' — it's the last line of defense against an election that may have been corrupted in some way," Neale said.
Finally, history isn't on Clinton's side.
"The argument can always be made that, 'Well, Secretary Clinton won the popular election, and therefore she should win the presidency.' This is the core argument of the direct popular election reform movement to eliminate the Electoral College," Neale said. "But that argument has been raised time and time again, and Congress hasn't acted on this proposal since 1979."
Plus, the few times a faithless elector has gone against their party's nominee, they've never swung an election.