LAS VEGAS — Nevada’s long crusade to block the creation of a national nuclear-waste dump at Yucca Mountain has pitted the state against a bipartisan group of lawmakers across the country, but a band of presidential hopefuls is joining the early voting state’s cause.

Nevada’s senior senator, Democrat Catherine Cortez Masto, has legislation that would bar the federal government from moving nuclear waste into a state without first receiving permission from the governor and local officials. Last year, Nevada’s two senators were the only sponsors of the measure.

This year, they’ve got company in Democratic Sens. Cory Booker of New Jersey, Kirsten Gillibrand of New York, Kamala Harris of California, Amy Klobuchar of Minnesota, Bernie Sanders of Vermont and Elizabeth Warren of Massachusetts.

The six senators’ move to establish opposition to the mothballed Yucca Mountain project is an appeal long made by presidential candidates hoping to win favor in Nevada, which holds a pivotal role as a swing state and the third state to vote in the Democratic presidential contest.

“Any candidate hoping to win the support of Nevadans must be against Yucca Mountain,” Cortez Masto said in a statement Friday in response to a question about the new co-sponsors.

The show of opposition to Yucca Mountain is “cyclical and obviously only on the Democratic side,” said Eric Herzik, chairman of the political science department at the University of Nevada, Reno.

Most Nevadans are opposed to storing the nation’s radioactive waste at Yucca Mountain, but it’s not a prime motivator among most voters and doesn’t resonate much outside of the state’s Democratic contests, Herzik said.

President George W. Bush gave the go-ahead in 2002 for tens of thousands of tons of highly radioactive spent nuclear fuel to be stored at the Yucca dump.

The move was unpopular in Nevada, where officials argue that seismic activity and nearby Air Force testing would make the site about 100 miles from Las Vegas unsuitable to safely store radioactive material from elsewhere in the U.S.

Despite Bush’s move, he still carried the state two years later when he ran for re-election.

President Trump was ambiguous on the issue as a presidential candidate but has since moved to restart the licensing process for the site after it was suspended under the Obama administration.

On Thursday, as Cortez Masto and Nevada Sen. Jacky Rosen testified in opposition to restarting the licensing project, Sanders issued a statement calling the Yucca Mountain plan “a geological, environmental, and social disaster” that must be abandoned.

Herzik said the stance on Yucca Mountain from the Democratic presidential candidates is expected, but it could become complicated as they campaign across the country in states eager to offload their nuclear waste.