By Andrew Chung and Lawrence Hurley

WASHINGTON (Reuters) – U.S. Supreme Court justices on Wednesday grilled lawyers advocating that “electors” in the complex Electoral College system that decides the winner of U.S. presidential elections are free to disregard laws directing them to back the candidate who prevails in their state’s popular vote.

If enough electors do so, it could upend an election, or, as some of the justices said, cause “chaos.”

The justices heard arguments in two closely watched cases – one from Colorado and one from Washington state – less than six months before the Nov. 3 election in which presumptive Democratic nominee Joe Biden challenges Republican President Donald Trump.

The justices also expressed concern over maintaining states’ ability to remove electors who have been bribed to vote for a particular candidate. On the other hand, the justices also pressed attorneys for Colorado and Washington state whether there are any limits on state powers seeking to control how electors vote.

The litigation involves the presidential election system set out in the U.S. Constitution in which the winner is determined not by amassing a majority in the national popular vote but by securing a majority of electoral votes allotted to the 50 U.S. states and the District of Columbia.

The cases involve so-called faithless electors who did not vote for Democratic candidate Hillary Clinton in the 2016 Electoral College even though she won the popular vote in their states.

Colorado and Washington state are among the 48 states – only Maine and Nebraska excepted – with winner-takes-all systems awarding all electors to the candidate who wins the state’s popular vote. The justices must decide if states can penalize faithless electors with actions such as monetary fines or removal from the role.

Thirty-two states and the District of Columbia have laws intended to control how electors vote. Only a handful enforce them with penalties.

Conservative Justice Samuel Alito wondered whether giving electors free reign “would lead to chaos” in instances in which an election is very close and “the rational response of the losing political party … would be to launch a massive campaign to try to influence electors.”

Conservative Justice Brett Kavanaugh asked whether the court should embrace the “avoid-chaos principle of judging, which suggests that if it’s a close call or a tie-breaker we shouldn’t facilitate or create chaos.”

Lawyer Lawrence Lessig, representing the Washington state electors, conceded that was a possibility.

Conservative Justice Clarence Thomas told a lawyer representing Colorado’s electors that a despite a promise to support the popular-vote winner an elector “can suddenly say, ‘I’m going to vote for Frodo Baggins,'” referring to the character from the fantasy novel Lord of the Rings.

The Electoral College vote, held weeks after the general election, is often overlooked as a mere formality in which the electors – typically party loyalists – actually vote for the winner of their state’s popular vote.

But in 2016, 10 of the 538 electors voted for someone else. While that number of so-called faithless electors did not change the election’s outcome, it would have in five of the 58 previous U.S. presidential elections.

State officials have said faithless electors threaten the integrity of American democracy by subverting the will of the electorate and opening the door to corruption. The plaintiffs said the Constitution requires them to exercise independent judgment to prevent unfit candidates from taking office.

“It’s somewhat hard to understand the concept of something I am pledged – bound – to do. I have made a promise to do something. But that promise is unenforceable,” liberal Justice Ruth Bader Ginsburg said.

Trump’s administration has taken no stance in the cases.

Chiafalo and another lead plaintiff Micheal Baca were Democratic electors who sought to persuade Republican electors to disregard their pledges and help deny Trump the presidency. Baca, who now lives in Las Vegas, was a Colorado elector. They cast their ballots for moderate Republicans and not Clinton.

Chiafalo was fined $1,000 by Washington state. Baca’s vote was canceled by Colorado officials. The electors argued that the penalties against them by their states violated the Constitution’s Article II and its 12th Amendment, which delineate the Electoral College process.

A lower court upheld Washington state’s fine against Chiafalo and two other faithless electors. Another court concluded that Colorado’s action against Baca violated his constitutional rights.

(Reporting by Andrew Chung in New York and Lawrence Hurley in Washington; Editing by Will Dunham)