The fact that the government officials are not revealing his political inclinations makes me think he's indeed a righoid. Otherwise why would they let this chance to purge the entire radical left go to waste?

Humor reflects your political opinion. People who make fun of blacks for example are racists. Leftists never make fun of social minorities they simply don't find it funny instead they target Christians and chuds etc.

The shooter made a joke about gay using gay as an insult.

This means he thinks gays are bad same as a /pol/ user making fun of jews or blacks etc