(CNN) —  

Sen. Kamala Harris of California said that if she’s elected president, she will back abolishing the filibuster if Senate Republicans stand in the way of legislation to combat climate change.

It’s the first time she has said as a 2020 candidate that she supports the end of the filibuster – the requirement that any legislation get 60 votes to end the Senate’s unlimited debate and bring it to a simple majority vote.

During Wednesday’s CNN climate crisis town hall, Harris slammed a Senate committee hearing “during which the underlying premise of the hearing was to debate whether science should be the basis of public policy,” eliciting murmurs from the crowd.

Harris said she would first seek to work with the GOP. However, she said, “if they fail to act, as president of the United States, I am prepared to get rid of the filibuster to pass a Green New Deal.”

Harris’ call for a filibuster comes on the heels of Senate Majority Leader Mitch McConnell bluntly warning Democrats last month against weakening the procedure.

“The legislative filibuster is directly downstream from our founding tradition. If that tradition frustrates the whims of those on the far left, it is their half-baked proposals and not the centuries-old wisdom that need retooling,” the Kentucky Republican wrote in an op-ed for The New York Times.

The filibuster is a concrete obstacle in Democrats’ path, as they would need to win the presidency and gain three seats in the Senate to take control of the chamber in the 2020 elections. But the party would need 60 votes – virtually an impossibility given the map of Senate seats up for election next year – to win a filibuster-proof majority. That means even if a Democrat is elected president and the party wins full control of Congress, Republicans would still have the ability to block legislation in the Senate unless the filibuster is done away with.

Fellow candidate Sen. Elizabeth Warren of Massachusetts made a similar call to end the filibuster in April, calling the procedure “a tool to block progress on racial justice,” according to excerpts of her speech.

CNN’s Chris Cillizza and Ted Barrett contributed to this report.