On the heels of landslide victories in Alaska, Hawaii, Idaho, Utah, and Washington, Bernie Sanders and his supporters are urging so-called “superdelegates”—Democratic party big-wigs who can support the candidate of their choosing on the convention floor—to join the revolution. 

After his recent wins, Sanders trails rival Hillary Clinton by only 268 pledged delegates, according to the Associated Press tracker. Meanwhile, Clinton’s lead among superdelegates is sizeable: she currently claims 469 to his 29.

“You’ve got superdelegates in states where we win by 40 or 50 points. I think their own constituents are going to say to them, ‘Hey, why don’t you support the people of our state and vote for Sanders?'”
Click Here: Golf special—Senator Bernie Sanders

But, as ABC News pointed out, the elected officials and party elites who hold superdelegate posts “can swap their vote at any point until voting takes place at the party convention and will face grassroots pressure—and pressure from the campaign—to back the will of their hometown voters.”

Indeed, Sanders said as much on CNN‘s “State of the Union” with Jake Tapper on Sunday.

“I think the momentum is with us,” he said, following Saturday’s three-state sweep. “A lot of these superdelegates may rethink their positions with Secretary Clinton.”

Campaign press secretary Symone Sanders added in an interview on Monday: “You can’t win like we won this past weekend and how we intend to continue to do well in these nominating contests and not expect superdelegates to take a second look. So we are focused on winning votes, winning the endorsement, if you will, of the American people. And we are hopeful and confident that those superdelegates will come along.”

Furthermore, the Vermont senator noted, many of the roughly 700 superdelegates have yet to state their allegiance.

“I think when they begin to look at reality, and that is that we…are beating Donald Trump by much larger margins than Secretary Clinton,” Sanders said on CNN. “And then you’ve got superdelegates in states where we win by 40 or 50 points. I think their own constituents are going to say to them, ‘Hey, why don’t you support the people of our state and vote for Sanders?'”

In Washington state, for example, where Sanders won close to 73 percent of the vote on Saturday, a majority of the 17 superdelegates have endorsed Clinton. A petition calling on those superdelegates to “Let the voters decide,” and to support their constituents’ wishes, has gathered close to 25,000 signatures as of Monday morning.

Alaska Democratic Party vice chairman Larry Murakami, who had previously donated to Sanders but formally had been uncommitted, told Politico on Monday that in the wake of Sanders’ 82-18 trouncing of Clinton in his state on Saturday, he too was backing the democratic socialist.

“I’m going with Alaska,” Murakami said. “I don’t know that any other of the Alaska delegates have committed to one candidate or another, but I think it’s totally appropriate if we’re over 80 percent for one of us to step forward and say, ‘yeah, I’m voting for Sanders like everyone in my district, like most of the people in my district and most of the people in Alaska’.”