If what Dobb & Conrad did broke no Senate rules, then the Senate rules are too weak.
The committee ignored sworn testimony that both knew they were getting special treatment. It's not a problem with the rules - it's a problem with the corrupt mandarins who are supposed to enforce them. The entire lot, save a few like Coburn, Inhofe, Demint and Sessions, needs to be voted out of office. The corruption is nearly as deep on the GOP side.