Sen. Bernie Sanders ruled out supporting Sen. Chuck Schumer for another term as Senate Democratic leader, while Sen. Elissa Slotkin said her vote remains unavailable without a concrete governing plan. Their Tuesday challenge came after sweeping midterm victories gave Democrats control of Congress.

Sanders and Slotkin pressed for a change in party leadership as Democrats prepared to govern with a new Senate majority. Sanders made his position absolute, while Slotkin left a narrow path for Schumer or another candidate to win her support.

Speaking at a news conference alongside Slotkin, Sanders acknowledged his long relationship with Schumer and praised his work ethic. Sanders then made the break clear: “But in my view, the time is now for change, and I will not be supporting Chuck to be re-elected as the Democratic leader.”

The declaration amounted to a public challenge as Schumer sought to keep leading Senate Democrats. It also ensured that the leadership election would not proceed without prominent senators raising questions about the party’s direction.

Schumer nevertheless remains the favorite to retain the position. He has cultivated longstanding relationships within the Democratic caucus and played a central role in the party’s successful campaign to reclaim the Senate.

Schumer and Sen. Kirsten Gillibrand helped with Senate campaign efforts by recruiting candidates and raising money for competitive races that ultimately delivered the Democratic majority. Sanders credited that work but argued that electoral success should not automatically guarantee Schumer another term.

Sanders framed the campaign victory as a broader effort involving more than party leadership: “I think Chuck and Kirsten raised a whole lot of money, which is a great help to many candidates, and I think they deserve credit. But I think there are a whole lot of people who were busy running around the country, holding rallies and supporting candidates.”

Slotkin stopped short of completely ruling out a future vote for Schumer. Her support, however, will depend on whether he or another candidate offers a governing plan that she considers meaningfully different.

“Whoever wants my vote is going to have to show me a concrete plan that’s definitively different,” Slotkin said. “I’m a no until and unless I see that from anyone.”

Slotkin also encouraged senators to consider withholding a quorum in the leadership election if only one candidate emerged. She tied that possibility to whether senators had received sufficient assurances about the direction of the party.

Schumer, who has served as Democratic leader since 2017, expressed confidence Tuesday that he would prevail despite the calls for change. He presented the caucus as united around a shared governing agenda.

Schumer defended his position directly: “I’m confident I will be elected majority leader, and our caucus is really united in focusing on bringing down costs, on ending the corruption, on ending the chaos, on ending the war. We have great unity in our caucus, and I’ll be proud to lead it as majority leader.”

Neither Sanders nor Slotkin is seeking the leadership job. Both identified Sen. Chris Van Hollen as a potential challenger to Schumer.

Van Hollen told MS NOW’s Ali Vitali at Groundwork Action’s “Popular Mandate” event Tuesday that he was “actively listening” to calls for new leadership. He has contacted colleagues about a possible bid but has not formally announced a challenge.

Slotkin called for an agenda centered on lowering costs, producing results during the first 100 days and giving newly elected senators a greater voice in leadership decisions. She also proposed creating a joint House and Senate committee focused on artificial intelligence.

Sanders pushed for more ambitious policies involving health care, economic inequality and foreign policy. His priorities included a broader debate about the war in Iran and U.S. military assistance to Israel.

Sanders said, “The time is now to deal with the need to create an economy that works for all, not just the people on top.” He also argued that Schumer had not been leading the party in that direction.

The Vermont senator suggested that a leadership contest could produce a nationally televised debate about the Democratic Party’s future. When asked whether an extended contest could divide Democrats after their victories, Sanders and Slotkin rejected the premise that debate would weaken the party.

Sanders answered with a defense of open argument: “This is a democracy. We believe in democracy, and that means a vigorous debate over the most important issues facing America.”

Slotkin warned against treating the election results as an unconditional endorsement: “People are so exhausted with Trump and so exhausted at the economic stress in their life that they’re willing to vote for anything different.” She added, “We have to earn their vote by what we do in January.”