The answer has to do, I think, with a lack of integrity, an absence of a moral compass, a narcissism in which the all-consuming need becomes to protect oneself and one’s boss.

Lack of integrity may also be the best way to capture the morphing scandal of the pre-election $130,000 payoff to a porn star to apparently keep quiet about an affair with Trump. It’s bad enough that Trump appears to have been cheating on Melania right after she had their baby (“Oh, don’t worry about her,” he is said to have told the actress). But with the payoff and reported cover-up, Trump is betraying all of us.

When The Wall Street Journal first reported the porn-star payout by Michael Cohen, Trump’s longtime lawyer, Cohen denounced the report as a “false narrative” of “outlandish allegations.”

Oops. Take two. This week, Cohen confirmed the payment in a statement saying that he “facilitated” the transfer with his own cash. It doesn’t seem quite true, as some news organizations reported, that Cohen precisely denied that he had been reimbursed. Cohen’s statement was artful. He denied that he had been reimbursed by either the Trump Organization or the Trump presidential campaign, but not that he had been reimbursed by someone else — say, by Trump himself. (The White House did not respond to my inquiry about whether Trump had personally paid the $130,000.)

Sometimes politicians, liberals and conservatives alike, are unprincipled in pursuit of principles they are passionate about. But Trump aides don’t seem to believe in any cause larger than themselves or their leader.

That’s alarming because of the risks that even worse might lie ahead. When self-absorbed people are caught in a growing scandal, they overreach. In this case, that might mean the firing of Robert Mueller or Rod Rosenstein, or some military clash that changes the subject. To be clear, I don’t think officials would deliberately turn to war as a solution to political problems, but we all have a remarkable ability to persuade ourselves that what is good for us is also good for the country.

Every administration suffers embarrassments. But when there is a basic lack of integrity at the top, these do not easily self-correct; rather, they build upon themselves because of an impulse to cover up and layer new deceptions on top of old deceit. That seems to be what is happening in both the Rob Porter and porn-payoff scandals.

The risk is that this stain continues to spread, metastasizing and bringing down everything around it. And to me, it looks as if the Trump administration is now metastasizing.