The fiasco undoing the Republican Party right now—induced by the fact that the man they nominated to be president is, among many bad things, a sex predator—can be attributed to two basic failures of political due diligence: the failure of Donald Trump’s Republican rivals in the presidential primary to conduct thorough opposition research on the frontrunner, and the failure of Trump to put himself through the same process.

It is also one of the most alarming indictments of both personal and partisan character in the history of U.S. politics. The GOP is exhibiting all of the flaws that deluded Trump into thinking a campaign for the presidency would be in his best interest.

At the highest levels of the Republican and Democratic parties, candidates face such intense scrutiny that they typically vet themselves to get a jump on their enemies. That is, their campaigns hire lawyers and investigators who scour all the forgotten corners of their lives, looking for any questionable activities that could be weaponized by the opposition.

Typically, sex predators never reach this level of politics because they don’t need a team of professionals to poke around and tell them that assaulting countless women and then bragging about it is a political loser. But if you can imagine a politician with such a broken moral compass and such a profound resistance to self-criticism that he didn’t consider behavior like this to be damning, and didn’t imagine that others might find it damning, the self-vetting process is the ultimate backstop. (Had Hillary Clinton subjected herself to self-vetting, her campaign might not have been caught so flatfooted by the revelation that she used a private email server to conduct public business as secretary of state.)

It stands to reason that if Trump’s team had turned up the information that is now pouring forth from his accusers and others, he wouldn’t have been able to mount even the shell of the campaign he’s run so far. Surrogates wouldn’t have attached themselves to him; staffers wouldn’t have accepted jobs with him; the Trump campaign would’ve been over before it started. It’s likely, too, that if any of the 16 other Republicans who sought the presidency had done an even halfway competent job investigating Trump’s past, they would have turned up enough information to smother his campaign in its infancy—at the very least, the people now running it wouldn’t be beset by panic about what kinds of horrifying things Trump might have said and done on tape over the past 40 years.