Inslee just commuted the sentence of a child killer from death to life, he is getting nowhere near a national ticket. There were issues earlier in his term with prisoners accidentally released early and murderers escaping psychiatric hospitals. He sounds like a Dukakis clone.
Neither of those things stopped him from re-election. Being anti death penalty isn't a deal breaker in American politics.
I think he's positioning for a run, and will try to go for the progressive vote. Doubt he gains any real traction with primary voters though, might be a better as a VP pick.