WASHINGTON • The Electoral College's 538 members gather on Monday at 50 state capitols to cast the ballots that matter the most when it comes to electing a United States president.

Normally sedate affairs that pass with little notice, this year's proceedings have been injected with a bit of drama and a dash of uncertainty with an unprecedented campaign by a small group of electors to overturn the results of last month's presidential election.

The attempt to deny Mr Donald Trump the presidency by trying to convince Democratic and Republican peers to back someone else is almost sure to fail based on history.

Behind the drive is a group calling itself Hamilton Electors, led by two Democratic electors from western states. The name is a nod to Mr Alexander Hamilton and his explanation of the need for the Electoral College, an entity the first US Treasury secretary said existed to make sure that "the office of the president will never fall to the lot of any man who is not in an eminent degree endowed with the requisite qualifications".

Mr Bret Chiafalo, an Electoral College member from Washington state who is a Hamilton Electors organiser, calls the institution the nation's "emergency brake" in a video that outlines the group's goals.

"If only 37 Republican electors change their vote, Donald Trump will not have the 270 electoral votes he needs to be president," he says. "Thirty-seven patriots can save this country."

If the effort to flip 37 Republican electors were to succeed, it could send the final decision to the Republican-controlled House of Representatives.

At issue is the idea of "faithless electors" - members of the Electoral College who vote with their conscience rather than their party's chosen candidate. That has never mattered before or been seriously tested because there have been few cases of "faithless electors" - the last occurrence was in 2004.

Mr Trump has a comfortable margin. He won the popular vote in 30 states, giving him a total of 306 electoral votes. Mrs Hillary Clinton carried 20 states and the District of Columbia with 232 electors. But nationally, she won the popular vote by nearly 3 million votes.

Under the rules, 21 states do not require Electoral College members to vote for their party's chosen candidate. But the other 29, plus the District of Columbia, say electors must support their party's candidate. Failure to do so invites punishment, such as a fine.

Most US states award all Electoral College votes to the winner of the popular vote in that state. Only a few allow the votes to be split among candidates.

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