Politicians are all liars. Here is an unbiased way to see how!
A while ago, I found out about Factcheck.org. They are an organization that essentially calls bullshit when politicians start mudslinging.
From the horses mouth:
We are a nonpartisan, nonprofit, "consumer advocate" for voters that aims to reduce the level of deception and confusion in U.S. politics. We monitor the factual accuracy of what is said by major U.S. political players in the form of TV ads, debates, speeches, interviews, and news releases. Our goal is to apply the best practices of both journalism and scholarship, and to increase public knowledge and understanding.
I strongly encourage to sign up on their site to get their email updates. They are especially relevant around election time as sort of a gut check to see if the jerk you are planning on voting for is really honest. Most arent 
