Who Cost The Republican Party The U.S. Senate? Probably The Libertarian Party

The Democratic Party will most likely have a trifecta in the federal government on January 20, 2021.
Democrats will control the presidency with former vice president Joe Biden set to take office. They will control the U.S. House of Representatives, as they have since the 2018 midterm elections, and they should have a slim 50-50 majority in the U.S. Senate with vice president-elect Kamala Harris serving as the tiebreaker, assuming West Virginia Democratic Senator Joe Manchin doesn't switch parties.