Well, I sure can't recall one that worked FOR us.
There have been a few, but they've all had to fight the same corrupt, entrenched good old boy Senate leadership club which we see today busily undermining people like Jim Demint and selling out the country to the globalists.
Demint is one, also Tom Coburn. From the past, Jesse Helms, and Jeremiah Denton. (a real Vietnam War hero and survivor of the Hanoi Hilton - research how he was treated vis a vis John Kerry)