U.S. Senator Barbara Boxer (D-CA) filed legislation Tuesday that would eliminate the Electoral College, so that presidential elections would be decided by the popular vote.

Boxer introduced the bill when the Senate came into session Tuesday, NBC News reported.

The move is in response to Donald Trump's presidential victory last week. The president-elect won through the Electoral College, although Hillary Clinton is leading the popular vote by nearly a million votes, a statement from Boxer's office read.

Trump won the presidency by securing at least 290 electoral votes while Hillary Clinton recieved 228, with two states still left to call, according to NBC News. Boxer was a Clinton supporter.

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"When all the ballots are counted, Hillary Clinton will have won the popular vote by a margin that could exceed two million votes, and she is on track to have received more votes than any other presidential candidate in history except Barack Obama," Boxer said.

Trump will be the fifth president in U.S. history to win the election despite losing the popular vote. George W. Bush won the most recent such election, in 2000.

"This is the only office in the land where you can get more votes and still lose the presidency," Boxer said in a statement. "The Electoral College is an outdated, undemocratic system that does not reflect our modern society, and it needs to change immediately. Every American should be guaranteed that their vote counts."

Four years ago, Trump called the Electoral College "a disaster for a democracy," in a tweet sent on Nov. 6, 2012.

The electoral college is a disaster for a democracy. — Donald J. Trump (@realDonaldTrump) November 7, 2012

In an interview with "60 Minutes" that aired on Sunday Trump said he wasn't going to change his mind about preferring an outcome where the person with the most votes wins "just because I won."

Still he added, "There’s a reason for doing this because it brings all the states into play. Electoral College and there’s something very good about that. ... I do respect the system."

On Tuesday morning, a week after the election, the president-elect sent two tweets conveying his support for the Electoral College, which he now calls "genius."

"If the election were based on total popular vote I would have campaigned in N.Y. Florida and California and won even bigger and more easily," he said.

If the election were based on total popular vote I would have campaigned in N.Y. Florida and California and won even bigger and more easily — Donald J. Trump (@realDonaldTrump) November 15, 2016

In a follow-up tweet he said: "The Electoral College is actually genius in that it brings all states, including the smaller ones, into play. Campaigning is much different!"

The Electoral College is actually genius in that it brings all states, including the smaller ones, into play. Campaigning is much different! — Donald J. Trump (@realDonaldTrump) November 15, 2016

If Boxer's amendment were to pass, it would amend the U.S. Constitution, and "would take effect when ratified by three-fourths of states within seven years after its passage in the U.S. Congress," the statement from Boxer's office read.

The bill is not expected to advance in the GOP-controlled House and Senate.

The LA Times reports that Boxer has previously sponsored legislation to repeal the Electoral College, but that those bills weren't considered.