> This is making a pretty big assumption that the long-term US energy mix is going to stay the way it is.

It's the stated goal of one of the parties to keep or increase fossil fuel usage, isn't it?

> Meanwhile the US administration flips parties every four to eight years

Magic 8 Ball says "yeah, in the past, 2028 isn't looking good though"

> next time they're Democrats they'll be trying to hasten that result

Which will be blocked and/or immediately overturned by the current/next Republic Congress/Senate/SCOTUS/President.