First, his sudden prominence sets up exactly the kind of stylistic contrast that Jeb needed: He and the Donald are now the two most famous names in the race, they’re occupying opposing poles (populist/establishment, raffish/respectable) in a way that makes Jeb look like the safest harbor for anyone freaked out by Trump’s success, and the longer Trump polls well the less attention (and, perhaps, fund-raising dollars) there will be for more plausible challengers.

At the same time, Trump’s deliberately-outrageous shtick, his camera-hogging instincts, are providing cover for Jeb to run the kind of primary campaign he clearly wants to run – conceding a human role in climate change here, doing minority outreach there – without having controversy dogging his every centrist foray.

Given his name recognition and fund-raising base, Jeb doesn’t need the media spotlight right now, and there was a real danger — visible in his fumbling answer to questions about Iraq — that he would become a punching bag for the entire field across the early debates. Now that seems less likely, because everyone is scrambling to figure out how to handle Trump instead.