Other than Cruz and Lee, who have tried to stop Obama's agenda?
If Republicans aren't stopping Obama and the progressive agenda in general, then they're dead to me.
Fine. You have identified 43 Republican Senators that need to be replaced. Should we start by letting some Dems take their place for six years?
If not, what should we do? Stay home? Vote Dem?
My advice:

It’s S.O.P. for the Rinos. Vote for cloture to get the 60 votes needed to get Socialist legislation they support to the floor. Then needing only 51 to pass the bill they vote against it knowing the Rats have the votes, so they vote against it and parade in front of the Cameras how devastating the bill/law will be.
Then after the day’ssession is over the Rats and Rhinos get together, swap spit and laugh their asses off at idiots that believe ANYTHING they are told!
Come election time they put out records of their votes on major legislation. Not one word about their votes that put the crap on the floor to be voted on however.