(CNN) — The Supreme Court said Monday that states can punish members of the Electoral College who break a pledge to vote for a state’s popular vote winner in presidential elections.

The case comes as the election season is heating up, putting the Electoral College once again front and center in an increasingly polarized and volatile political atmosphere.

In 2016, 10 of the 538 presidential electors went rogue, attempting to vote for someone other than their pledged candidate. In all, 32 states and the District of Columbia have laws that are meant to discourage faithless electors. But until 2016, no state had ever actually punished or removed an elector because of his or her vote.

The vote count was 9-0.

“Today, we consider whether a State may also penalize an elector for breaking his pledge and voting for someone other than the presidential candidate who won his State’s popular vote. We hold that a State may do so,” Justice Elena Kagan wrote.

“The Constitution’s text and the Nation’s history both support allowing a State to enforce an elector’s pledge to support his party’s nominee — and the state voters’ choice — for President,” she added.

The ruling was “not surprising,” said Steve Vladeck, CNN Supreme Court analyst and professor at the University of Texas School of Law.

“Given the potential implications of a holding that electors could vote for anyone they chose, it’s not surprising that the justices held that states can prevent them from doing so,” Vladeck said.

“The only surprise is the unanimous vote in cases at least some expected to divide the Court,” Vladeck added. “Here, at least, concern over the consequences of a contrary ruling appears to have united the Justices.”

Three presidential electors in Washington state, for example, voted for Colin Powell in 2016 rather than Hillary Clinton and one voted for anti-Keystone XL pipeline protester Faith Spotted Eagle. A $1,000 fine was upheld by the state Supreme Court.

In Colorado, the legal outcome was different when Micheal Baca sought to vote for John Kasich instead of Clinton.

Baca’s vote was rejected and he was removed and replaced with a substitute who voted for Clinton. Baca was referred for potential perjury prosecution, although no charges were filed. He filed suit, and ultimately won when the 10th US Circuit Court of Appeals held that while the state does have the power to appoint electors, that does not extend to the power to remove them.

During oral arguments, Frodo Baggins, a hobbit from the “Lord of the Rings” trilogy, became a part of the court’s historical record.

In a line of hypothetical questioning, Justice Clarence Thomas used Baggins as a case study.

“The elector who had promised to vote for the winning candidate could suddenly say, ‘You know, I’m going to vote for Frodo Baggins. I really like Frodo Baggins.’ And you’re saying, under your system, you can’t do anything about that,” Thomas asked Baca’s attorney, Jason Harrow.

“Your honor, I think there is something to be done, because that would be a vote for a non-person. No matter how big a fan many people are of Frodo Baggins,” Harrow said.

In the opinion, Kagan walked through the history of the Electoral College, referencing the presidential election in 1796 in which John Adams came in first among the candidates and Thomas Jefferson second.

Kagan managed to weave together a dilemma of the founding era with a popular political comedy that ran on HBO. (HBO is owned by CNN parent company WarnerMedia.)

“That meant the leaders of the era’s two warring political parties—the Federalists and the Republicans—became President and Vice President respectively. (one might think of this as fodder of the new season of Veep),” she wrote.

And Kagan, one of the most lively writers of the court, also referenced Lin-Manuel Miranda’s Broadway musical “Hamilton.”

“Alexander Hamilton secured his place on the Broadway stage—but possibly in the cemetery too—by lobbying Federalists in the House to tip the election to Jefferson, whom he loathed but viewed as less of an existential threat to the republic,” Kagan wrote.

Thomas agreed with Kagan, writing that “nothing in the Constitution prevents States from requiring Presidential electors to vote for the candidate chosen by the people.”

There is an elector for every member of the House of Representatives, the Senate plus an additional three for people who live in the District of Columbia. It takes 270 votes to get a majority of the Electoral College. If there is a tie or nobody gets to the majority, then the election goes to the House of Representatives.

“This has become a big deal because there is a large risk that for the third time in this century, the popular vote winner and the electoral vote winner will be different people,” said Reed W. Hundt, who runs a foundation called Making Every Vote Count.

To Lawrence Lessig, a Harvard Law professor behind the challenges, it was clear that while the state has the power to appoint a slate of presidential electors who are members of the same party as the ticket that wins the popular vote, those electors, once appointed, can cast their votes however they like.

He argued that if the court allowed states to step in to penalize the electors, it could have unexpected consequences. For instance, a state might feel free to take more drastic steps, including passing laws to bar an elector to vote for a candidate who has not released a copy of their tax returns.

Lessig, who is also a founder of the advocacy group Equal Citizens, said in a statement that Monday regardless of the case’s outcome it was critical to resolve the question before “it created a constitutional crisis.”

“Obviously, we don’t believe the Court has interpreted the Constitution correctly. But we are happy we have achieved our primary objective — this uncertainty has been removed. That is progress,” he wrote.

Washington state Attorney General Robert Ferguson told the justices that since the creation of the Electoral College, there have only been 165 faithless electors representing less than 1% of the Electoral College votes cast for president. Of those, 71 changed their vote in 1872 and 1912 because the candidate they pledged their vote for died.

“The scattered examples that remain have been largely symbolic gestures with no chance of impacting results,” Ferguson said, adding that “over the last century, no elector for a winning presidential candidate has switched votes to the losing candidate.”

This story has been updated to include additional background information and reaction.

The-CNN-Wire™ & © 2020 Cable News Network, Inc., a WarnerMedia Company. All rights reserved.