Schwarzenegger is angry because Trump is doing something he could never do, go from being a jokey celebrity to having a legit chance at being President. Schwarzenegger would jump at the chance to be in Trump's shoes now, but it won't happen because he's a foreigner, so he's salty.
That's probably true. But can't deny he'd give it his best shot because of that reason, and likely would be due to win right now.
