The Bush campaign investigated the consequences of renouncing Trump as the potential Republican nominee outright, which several Bush donors and friends have reportedly suggested in recent months. The campaign disputed an account by Politico that indicated Bush had planned to announce he would not support Trump during Tuesday night’s debate in Las Vegas – because it’s against the rules.
But campaign officials did go so far as to investigating the consequences of refusing an endorsement, which they concluded would have resulted in Bush falling off the ballot in South Carolina, Kentucky and Utah because of state party rules.
Bush has repeatedly rejected the idea that Trump will win the GOP nomination.
"It's a hypothetical, and I reject, out of hand, that he's going to be the nominee," he told voters in Hooksett, N.H. last week -- echoing similar lines he's delivered at town hall rallies and in interviews.
Supporters suggested on Wednesday that while Bush won't formally withhold support for Trump, his debate performance should signal how deeply the former Florida governor detests the New York businessman and his proposals.
Separately, supporters have urged and pundits have surmised that the super PAC supporting Bush, Right to Rise USA, should direct the tens of millions of dollars it has remaining in its accounts at Trump by unleashing a series of television attack ads. But Mike Murphy, who leads the PAC, so far has dismissed such suggestions. Last week in the wake of Trump's call to temporarily ban most Muslims from entering the country, the PAC began airing an ad that called Trump "unhinged." But it also attacked the records of Sens. Marco Rubio (R-Fla.) and Ted Cruz (R-Tex.).
Trump, who was characteristically dismissive of Bush during Tuesday night’s debate, said Wednesday that Bush’s comments were coming from desperation, not principle.
“While everyone said I beat him last night, I was only responding to his desperate attempt to stay relevant by attacking me,” wrote Trump. “Jeb is only doing this because I committed to run as a Republican last night -- so dishonorable.”
Jose A. DelReal contributed to this story.