What can Donald Trump do to stop morphing into Joe Biden? The two presidents could hardly be more different in most ways—but in the one that counts most with voters, Trump is in danger of resembling his predecessor. Americans rejected Biden and the Democrats last year because they were incensed at the lousy state of the economy. Right now, they’re not much happier with Trump’s economy. Inflation was the No. 1 concern on voters’ minds last year, and it’s still a top concern today. Trump’s team say they plan to tout “affordability” as a theme Republicans can win on in...