Moments after Donald Trump tapped freshman senator J. D. Vance as his 2024 running mate during this year’s Republican convention in Milwaukee, Republicans in the convention hall were already feeling giddy about the prospect of watching him debate Vice President Kamala Harris. “I will personally set up a folding table to sell tickets to the debate,” Wisconsin GOP chairman Brian Schimming told National Review inside the arena that night. A couple weeks later, everything changed....