One who sucks the proverbial cock of the billionaire Koch brothers. Bonus points for also being a 'sucker' by falling for a prank call from someone posing as a Koch brother.
Hey, are you voting to re-elect Scott Walker?
No way! He's a dirty, rotten Kochsucker!
A kochsucker is anyone involved in politics who advocates policies that benefit corporations, big business and right wing interests, under the guise that those policies will actually benefit normal Americans. Very similar to a teabagger.
Did you hear that kochsucker claim climate change is hoax? Yeah, probably so that his oil polluting buddies can get another no bid oil drill contract.