Sen. Chris Van Hollen, D-Md., announced Thursday that he will run for Senate majority leader, becoming the first senator to formally challenge Sen. Chuck Schumer, D-N.Y., for the top leadership post.

"In this election, the American people called for change. They called for a change from Donald Trump's disastrous policies, but even bigger than that, a change from the status quo that isn't working for working people," Van Hollen said in a statement.

The bid follows efforts by grassroots progressives, and some newly elected Democratic senators, to recruit Van Hollen as an alternative to Schumer. "It's now on us to meet this moment, and to do that we need new leadership," he said. "This is not about any one person, it's about answering the call of the American people. That is why I'm running for Senate Majority Leader."

Schumer, who has led the Senate Democratic caucus since 2017, remains favored to keep the job, but the contest is likely to be the most serious challenge he has faced. Democratic senators will choose their leaders for the next Congress in a closed-door vote in December, decided by a simple majority of the caucus.

In an interview Thursday night with MS NOW, Van Hollen said more than 10 senators have pledged to back him, while conceding he is the underdog. "Now people will have to make a decision, one way or the other, and they have to decide whether they want to vote for change or whether they want to vote for the status quo," he said.

According to his team, Van Hollen plans to campaign on using every available tool to end the Iran war, starting with the upcoming government funding measure to avert a December shutdown. He is also proposing to reverse President Donald Trump's "big, beautiful bill," get money out of politics and tackle corruption.

Van Hollen, 67, was first elected to the Senate in 2016 after serving in the House beginning in 2003. Schumer, 75, has spent longer on Capitol Hill: he was first elected to the House in 1980 and moved to the Senate in 1999.

Schumer responded to the announcement on X, writing that he welcomes "any discussion about the future of our caucus" and pointing to the election results. "I'm proud of what we've accomplished together, 55 seats and counting is an amazing result, and I have the votes to continue serving as Democratic Leader," he said.

Sen. Bernie Sanders, I-Vt., said Wednesday he would back Van Hollen in an official bid, a day after saying he would not support Schumer because "in my view, the time is now for change." After the announcement, Sanders wrote on X that voters "want a Democratic Party that will stand up to powerful special interests, take on the billionaire class and fight for working families." Sen.-elect Abdul El-Sayed of Michigan also endorsed Van Hollen, writing that he had urged him to lead the caucus as a candidate back in April and that Democrats "will require bold leadership."

Other senators rallied behind Schumer. Sen. Angus King, I-Maine, called him "one of the principal architects of the most successful election in modern history" and asked, "Why would you fire the manager when you just won the World Series?" Sen. Kirsten Gillibrand, D-N.Y., who led Senate Democrats' campaign arm this cycle, credited Schumer with directing resources that helped register 100,000 new voters in Mississippi, where Sen.-elect Scott Colom won a stunning victory. "That takes vision. It takes clarity of thought. It takes strategic leadership," Gillibrand said, predicting "enormous gratitude" for Schumer despite the grumbling.