Really, you can’t make this stuff up.
First, America elects a one term senator their president. That Senator happens to be an African-American and he also happens to have flipped N.C., Ind., Fla., Va., Ohio, N.M. and Nev. from red to blue.
Then the senator, now President-elect, picks several fellow senators to join his administration, creating several vacancies. In the Senate, unlike the House where the states hold special elections, the vacancies are filled by Governors. (This is a relic of the time when state legislatures picked Senators. It’s a compromise which was established as part of the creation of the 17th amendment in 1913.)