party [U.K.] may deserve to be punished, their political opponents don’t deserve to be rewarded.
Well, Paul Krugman didn't actually call it a fallacy, but he did write that either-or is not always a good solution. He wrote about the financial crises:
But here’s the thing. While Mr. Brown and his party [U.K.] may deserve to be punished, their political opponents don’t deserve to be rewarded.
- "Gordon the unlucky", New York Times, 2009-06-07
Next time you vote, remember that there could be a third, or fourth, or ... way.