Illegal aliens. That shit will be so easy.
Argue their effects on taxes, how many of them have stuff to do with drugs, and how legalizing weed may keep a lot of them out. There are SO many things you could write about illegal aliens and the shit related to them.
You could also do legalization of marijuana. I think that would be fairly easy. Argue how it would help stop illegal pot farms, having to deal with sketchy people, how it would effect the economy, and do tons of commentating.