It wasn’t just the Donald that did him in. In an alternate universe, Jeb Bush would currently be preparing for the most trying half year of his life. The former governor of Florida was the favorite to be the Republican nominee for president. But his strengths — a famous last name, deep pocketed donors, and a well-regarded brand of thoughtful conservatism — were overwhelmed by other factors. It wasn’t just a bombastic billionaire who seemed hell-bent on humiliating Jeb at every turn. It was also something far simpler: his last name.

“Our whole issue was related to dynasty or this sort of tough factor,” Tim Miller, Jeb’s former communications director said. “And neither of those things are fixable.”

In the latest episode of our “Candidate Confessional” podcast, Miller, who accompanied Jeb on most of his travel and was among the inner circle of advisers, pulled back the curtain on what went wrong for the campaign. In the process, he laid bare some troubling conclusions for a Republican Party that stands on the verge of choosing that bombastic billionaire — one Donald J. Trump — as its presidential nominee.