Has a lot to do with the 17th Amendment, which ended the legislatures choosing the Senators to direct popular election. This cut off the line of communication between state legislatures and the national legislature, an important function in a republican form of government. Additionally, it also dramatically increased the level partisanship as it turned the Senate into a version of the House but with 6 year terms. The House was supposed to be partisan hence the 2 year terms.
Turtle had to be half-brain dead and drooling in his Cream of Rice before FINALLY retiring.
UpChuck and Sanders will croak in Office before leaving.