"Dems want small government when it comes to marijuana legalization..."

This isn't really true. The legalization involves local and state regulation and taxes. Sure, the law is more lenient in that one can legally sell and buy the product, but it comes with substantially more regulation (you now need a department to do inspections audits etc).

"chafes at the idea that states could legalize marijuana unilaterally"

Technically they can't legalize it. They can do so at the state level, but it can still be illegal at the federal level. The thing is, the feds don't have the resources to enforce all the laws they make.

I do agree that most political parties and figures can be hypocritical.