Democrats won one U.S. Senate race in Georgia and surged ahead in another on Wednesday, moving closer to a stunning sweep that would give them control of the chamber and the power to advance President-elect Joe Biden’s policy goals.

Raphael Warnock, a Baptist preacher from the historic church of Martin Luther King Jr., beat Republican incumbent Kelly Loeffler to become the first Black senator in the history of the deep South state. Jon Ossoff, a documentary filmmaker who at 33 would become the Senate’s youngest member, held a narrow lead over incumbent David Perdue in the other race, with a final outcome not expected until later on Wednesday at the earliest.

The results were a repudiation of outgoing President Donald Trump in a state his Republicans have controlled for decades.

Trump campaigned for both Republicans in Georgia on Monday. But his support was overshadowed by the two months he has spent trying to subvert his own presidential election loss, with false accusations of fraud, including attacks on Republican officials in the state.

Later on Wednesday, Congress will meet to certify Trump’s election loss over the objection of a number of Republican lawmakers who have said they will try to reject some state tallies though there is no chance of success.

With 98% of votes counted, Warnock was ahead of Loeffler by 1.2 percentage points, roughly 54,000 votes, according to Edison Research. Ossoff led Perdue by more than 16,000 votes.

Winning both contests would give Democrats control of the Senate, creating a 50-50 split and giving Vice President-elect Kamala Harris the tie-breaking vote once she and Biden take office on Jan. 20. The party already has a narrow majority in the U.S. House of Representatives.

If Republicans hold the second seat, they would effectively wield veto power over Biden’s political and judicial appointees as well as many of his legislative initiatives in areas such as economic relief from the coronavirus pandemic, climate change, healthcare and criminal justice.

Trump’s relentless but flailing efforts to overturn the election in Georgia and nationally will move to Congress on Wednesday, when Vice President Mike Pence presides over the counting of electoral votes to certify Biden’s victory.

Trump’s supporters plan to rally in the streets of Washington. Trump has repeatedly called on Pence to throw out the results in states he narrowly lost, although Pence has no authority to do so.