If you’ve scrolled social media lately, you’ve likely seen Democrats cheering California Gov. Gavin Newsom for trolling Donald Trump. Whether it’s his all-caps posts, his red hats emblazoned with “Newsom Was Right About Everything,” or his willingness to spar with right-wing culture-war fixations like the Cracker Barrel rebrand, Newsom has been telegraphing his ambition to be Trump’s foil well before 2028. That performance has Democrats buzzing about him as a future national stand...