If Trump loses to Clinton, it’s not likely to elevate Cruz to the frontrunner for the 2020 Republican nomination. He will have too many enemies. Trump and his followers will still be around. They’ll be angry at Cruz. And Trump will continue to be a fixture on TV, commenting on everything. He’ll find time to attack Cruz. His fans will be active online. They’ll tweet furiously. It will never stop.

Fair or not, Cruz will be seen by the Trump constituency as a spoiler. Yes, he had been provoked by Trump during the primaries. Trump criticized his wife and linked his father to the assassination of John F. Kennedy in Dallas—inexcusable insults. But politically speaking, Cruz would be better off having been less public with his non-endorsement. He could have disclosed it in a venue other than a convention filled with Trump’s most fervent supporters. Or he could have said nothing.

There’s a loose historical precedent for Cruz’s defiance of his party’s nominee. In 1964, New York governor Nelson Rockefeller shunned Barry Goldwater, the GOP nominee. Richard Nixon, who’d lost to JFK in the 1960 race, endorsed Goldwater and campaigned for him.

Both Rockefeller and Nixon wanted to be president. Nixon was elected in 1968. Rockefeller became Gerald Ford’s vice president in 1974, by appointment. Knowing a lot of Republicans didn’t want him on the ticket, he withdrew from consideration before Ford ran for reelection.