If you think there is a difference between the parties go sit in on a congressional session and watch them vote on a 'highly-partisan' issue.

A majority of everyone votes one way, the bill passes and then politicians raise their hands and say 'hey actually I want to change my vote to be recorded as a nay.'

So the only way to know how someone actually voted is to go see it live.

If voting someone into office could actually change anything, they would never let us do it.