I probably got your attention now. Before you handwave me as a dumbass, hear me out. You might learn something if you do.
This seems contradictory, but if you actually read Marx and decided to follow his beliefs, you would vote republican.
Yes, Marx despised capitalism. However, he believed that the effective way of ending capitalism would be to let it run it's course. When capitalism brought things to hell, the proletariat masses would then bring about the revolution and start the transition from capitalism to utopia.
As a matter of fact, Marx thought that capitalism had to come before communism.
Thus, according to Marx, since voting republican would bring "capitalist" policy, you are speeding up the establishment of the communist society you dream of.