Sen. Chris Van Hollen of Maryland said Thursday he would challenge Sen. Chuck Schumer of New York for the leadership of Senate Democrats, setting up a contest for the position that will control the chamber’s floor agenda when the new Congress convenes in January. Van Hollen announced his decision in an interview with The Washington Post, a little over a week after Democrats regained the Senate in the midterm elections.

Schumer, who has led Senate Democrats since 2017, told The Associated Press last week he expected to win another term as leader. After Van Hollen entered the race, Schumer said he welcomed a discussion about the caucus’s future, the AP reported. The challenge gives Democratic senators a choice about how to use their majority while Republican President Donald Trump remains in office.

Van Hollen argues the election calls for change

Van Hollen told the Post that the election reflected a desire for change and that Democrats now have to deliver on it. The Maryland senator had called for a discussion of leadership but initially said he was uninterested in the role, according to the Post. He said he reconsidered as progressive groups and some newly elected Democrats urged him to run. He previously spent 14 years in the House and was elected to the Senate in 2016.

Schumer enters the race as the incumbent leader after a strong election for his party. Sen. Angus King of Maine, an independent who caucuses with Democrats, publicly backed Schumer after the challenge was announced, pointing to the party’s election performance, the AP reported. Van Hollen acknowledged to the Post that he faces an uphill race. Public endorsements give some indication of each senator’s support, but the outcome will depend on the members of the conference.

The caucus makes the decision

Under the Democratic rules, the party’s conference selects and confirms its officers without a vote of the full Senate. The rules provide for leadership elections no earlier than December before the start of a new Congress, except when a vacancy occurs. Both parties choose their floor leaders through their respective conferences, according to the Senate. The majority leader is the floor leader of the party that holds the majority.

That distinction matters in the weeks before January. The Senate’s current leadership roster lists Republican John Thune as majority leader and Schumer as Democratic leader. Thursday’s announcement starts a race for leadership in the incoming Congress. It leaves the floor leadership of the present Senate in place during the remaining weeks of the current Congress. The conference contest will establish who speaks for Democrats and coordinates their floor strategy when control changes.

The vote for leader is one part of organizing the incoming Senate. The Senate’s history describes a role that grew out of the parties’ own organization and gradually acquired floor powers. The conference’s own rules also make the Democratic leader its chair. That gives the winner responsibilities both in meetings of Democratic senators and in negotiations over what the chamber takes up.

Control of floor time raises the stakes

The majority leader works with committee chairs and ranking members to schedule floor business and call up bills. The Senate’s official account of the office also describes how the majority leader works with the minority leader on agreements that divide debate time and determine how a measure moves. When several senators seek recognition together, the presiding officer recognizes the majority leader first. That gives the leader the first opportunity to offer an amendment or make certain motions.

Those tools can determine which issues receive attention first and how a party presents its priorities. The ability to schedule a bill leaves the leader with the separate job of assembling the votes to advance it. That is one reason the debate over leadership involves both a governing agenda and the ability to keep senators with different political interests working together. The party’s conference will be weighing those questions even before its new majority takes office.

Senators face competing demands after the election

Progressive pressure for a change in leadership was visible Thursday beyond Van Hollen’s announcement. The Guardian reported that protesters at Schumer’s Washington office called for different leadership and pressed Democrats to prioritize ending the filibuster. That demand came from the protesters. Schumer’s supporters, including King, pointed instead to the results achieved under his leadership, according to the AP. Their arguments put different weight on the leader’s role in winning a majority and what the caucus should do with it.

The next indication of the race’s direction will come from senators who make their preferences public and from the candidates’ discussions with members ahead of a vote. Under the conference rules, the decision belongs to the caucus. The result will determine who begins January with responsibility for turning the party’s election promises into a Senate calendar, negotiating with Republican leaders and keeping Democratic senators together on the votes that follow.