Trump’s leaving his beleaguered staff with an impossible cleanup job. Photo: Joe Raedle/Getty Images

Watching Donald Trump’s campaign bob and weave and run in circles in response to the hailstorm of damaging revelations against him recently — ranging from his business losses in the 1990s to the allegations of sexual misbehavior and even crimes pelting him almost hourly right now — you’d almost think they did not see any of this coming.

Turns out they probably didn’t, because their candidate wouldn’t let them dig around in his past for potential vulnerabilities.

As Bloomberg’s Kevin Cirilli reported today, Trump repeatedly shut down efforts by his campaign staff — including the usually warring Corey Lewandowski and Paul Manafort — to conduct the self-research (or as some call it, “forensic evaluation”) necessary to plan for incoming fire.

Yeah, there was a superficial vet of Trump and the rest of the presidential field by the RNC at the beginning of the cycle. But nothing appropriate for a candidate who had been a fixture in tabloids for decades and who was known for — and promoted himself via — womanizing habits, controversial talk, and sharp business practices.

This year there has been almost daily reason to marvel at what my colleague Jonathan Chait has called the “garbage fire” of Trump’s campaign — a pattern of managerial incompetence and strategic cluelessness. But this might take the cake. The kind of anticipatory research Trump kept rejecting is standard practice in any campaign involving anyone who has been in the public eye or who might have skeletons in the closet, however small. Trump knew full well he had an army of skeletons large enough to beat ISIS if they were brought to life and weaponized. Yet he insisted that no staffers, even his most trusted advisers, could peek inside.

Maybe Trump was determined to show he did not really need a campaign — that his most effective tactic was to put himself out there and let his awesomeness do all the work. Turns out America is getting to know the mogul better every day.