President Donald Trump is set to face a Democratic-controlled Senate when the new Congress convenes in January, creating a sharp change in the path for his judicial nominees. The Senate confirms federal judges and Supreme Court justices, giving the incoming majority leverage over whether nominees advance.

Senate Democratic leader Chuck Schumer told The Associated Press that Democrats would oppose Trump nominees he considers unacceptable, including a potential Supreme Court pick. He did not say whether he would keep a future vacancy open until after the 2028 presidential election, as Republicans did with President Barack Obama’s nominee in 2016.

Democrats are expected to hold at least 54 Senate seats, according to AP and Reuters, with the final margin depending on outstanding results. The change in control is set to take effect on Jan. 3, when the next Congress begins. Republicans still have a lame-duck session before then, and Reuters reported that GOP leaders are seeking to advance pending judicial nominees before leaving control of the chamber.

The shift could slow confirmations across the federal courts. Reuters cited legal experts who expect Democrats to scrutinize nominees more closely and said district court vacancies could require negotiations between the White House and Senate Democrats. The Senate majority can block a nominee, though the exact path will depend on the nominee, committee proceedings and votes in the full chamber.

The Supreme Court itself has no announced vacancy. Justices Samuel Alito and Clarence Thomas have not publicly indicated plans to retire imminently, AP reported. That leaves the immediate political focus on pending lower-court nominations and on how the new Senate majority will handle any future opening on the high court.

Sources: Associated Press; Reuters.