Gaming out how Trump — a bombastic figure who refuses to abide by usual the rules of political decorum — will present himself has become a growing subject of speculation in Bush’s world. During one recent phone call with a political ally, Bush pointedly asked about the surging real estate mogul. What, the friend recalled the former governor wondering out loud, was behind Trump’s antics, and what was he trying to accomplish?

“Trump presents a challenge for Bush because he’s a hand grenade,” said Nelson Warfield, a longtime Republican strategist who has prepared a number of candidates for debates. “His people understand that and will be prepared for anything that comes their way.”

As the Aug. 6 debate grows closer, some Republicans are relishing the prospect of Trump tearing the bark off the former governor — or, at the very least, trying to trip him up. “Trump has one target and one target only,” said an adviser to a rival GOP candidate. “He’s going to bring a lawn mower for Bush.”