Joe Walsh isn't gonna win against Trump. Sorry. The people who support the GOP have officially rode the Trump train to madness and now anybody who doesn't match that same level of cruelty, lack of rationality and just overall crass disposition will not get that vote. The Republicans have spoken. They aren't looking for moderates. Seemingly every other politician with the R in front of their name have adopted Trump's xenophobia and haphazardly apporach to governing, which includes scapegoating minorities, blaming immigrants for problems with the economy, and embracing white nationalism.
And I've seen Joe's "transformation" on twitter...it seems like Trump made this guy "wake up" so to speak and not want to support him.
Seems the more "sane" republicans left the party after they realized Donald turned it into something they couldn't get behind at all.