suicide voter 

Someone who because they are naïve or just plain ignorant consistently votes against their own self-interests

Joe is a suicide voter he used to have a good job at a factory with a strong union that provided excellent pay and benefits, but he voted for an anti-union governor who busted up the union, resulting in a huge drop in pay, then he voted for a "free trade" Congressman who wants to move all factories to China. Now unemployed and receiving healthcare through the state exchanges created under the Affordable Care Act he plans to vote for a president who wants to take away his healthcare.

suicide voter by Just_sayin' October 12, 2015

Suicide Voter 

Voters who vote for the opposite general election candidate if their own party nominates someone other than their choice in the primary.

Suicide voters believe in 'my way or no way'.

Suicide Voter by The Eskimo February 6, 2008