It’s a convention of the states, where 2/3s of the states have to send delegates on a specific subject. Any amendments have to get approved by 3/4ths of the states. It’s highly controlled and highly unlikely left-wing ideas would get through that process. Hell, it’s tough to get wildly popular ideas like term limits through that process.
I don't know why that's so "unlikely" in a country that elected Obama twice. Especially one that reelected him despite his terrible track record. I think its a VERY risky proposition.