If you want to "bribe" someone, you don't hand them cash. You fly them to that industry conference in Hawaii in February. You give their spouse a non-job. You give them great interest rates on loans. You help their kid get into college. You buy the house next to theirs, tear it down, and make it a beautiful, lush lawn.
* Those are all real situations.
Protip: This is not a Republican vs Democrat issue.. just people getting massive kickbacks for using their power in specific ways.