Why is it legal for Congressmen to take bribes in exchange for voting for/against legislation?

Surely our Founding Fathers would have turned green and sick at the very thought of that?Why is it legal for Congressmen to take bribes in exchange for voting for/against legislation?It is not legal. It is a crime.Why is it legal for Congressmen to take bribes in exchange for voting for/against legislation?because the voters are stupid.....and prefer to spend their time on Yahoo Answers insulting the other side.