I don’t get this whole “junior, senior” nonsense. Seems to me all Senators and Congressman are equally elected by the electorate and there shouldn’t be a situation where a “junior” member has to kiss ass of a “senior” member. All of that stuff seems to have nothing in common with the founding documents and has just become accepted practice.
Any member can be elected leader, its just that senators with a lot of seniority are unlikely to vote for a senator without much seniority. There have been the positions of majority and minority leader since 1920, and you’re right, it is a tradition.
The Founding documents place Joe Biden in charge of the Senate as its constitutional “president.” Nobody wants that! Probably not even Joe!