“As you know, we’re under siege,” President Donald Trump told the rapt attendees of Ralph Reed’s Faith and Freedom Coalition conference last June. The audience heard “we,” but the president was likely speaking about himself. The president’s persecution complex is infectious and it’s leading Republicans around Trump to make decisions they will regret for years to come.

Most presidencies tend to develop a siege mentality over time, but the Trump administration appeared to enter office with a chip on its shoulder. It was an accidental presidency in those early days, improvisational and reckless. It was burdened with vainglorious sponges who whose egos exceeded their abilities. Most of all, it was paranoid. Those criticisms the president and his administration endured in the early months were earned, but that made for an insular organization fixated on loyalty and tribal moiety. It didn’t help matters that the president who managed affairs was himself prone to conspiratorial thinking. From the political press to the “deep state” to the president’s own Justice Department, Trump’s imagined enemies haunted him.

Despite the defenestration of most of the sycophants that staffed the nascent Trump administration and reinforced the president’s paranoia, the bunker mentality persists. This predisposition has several effects. It has instilled in Trump’s supporters the same cageyness that afflicts the president. It has also led the White House to close ranks even to its own detriment. That impulse perhaps explains the bizarre and sordid story involving the belated resignation of White House Staff Secretary Rob Porter.

Porter allegedly beat women. According to a Daily Mail report published Wednesday, he emotionally and physically abused his ex-wives—one of whom provided photographic evidence to prove it, which she also shared with the FBI. Porter purportedly tore one former spouse naked from a shower, forced his hand through panes of glass in fits of rage, and compelled another ex-wife to seek legal redress after he violated the terms of their separation agreement by menacing her in her apartment. The temporary protective order she received in 2010 concluded that “reasonable grounds exist to believe that [Porter] has committed family abuse and there is probable danger of a further such offense.” The White House knew about all of this. The FBI informed the White House of the allegations against Porter as early as November. One of Porter’s ex-girlfriends expressed her concerns about him directly to White House counsel Don McGahn. Still, it’s principals rallied to Porter’s side.

“Rob Porter is a man of true integrity and honor, and I can’t say enough good things about him,” White House Chief of Staff John Kelly initially said of his deputy in a statement released Wednesday. “I am proud to serve alongside him.” The statement was reportedly co-drafted by White House Communications Director Hope Hicks, who was involved in a romantic relationship with Porter. White House Press Secretary Sarah Huckabee Sanders echoed Kelly, calling Porter a man of “the highest integrity and exemplary character.” If Porter had to go, the plan was for him to stay on for at least several more weeks. But the demands for Porter’s job grew louder when it was revealed by unnamed officials in the White House that Kelly was aware of the charges against Porter, which is one of the reasons why his deputy had repeatedly failed to obtain a security clearance. Nevertheless, officials inside and outside the White House urged Porter to “stay and fight.”

Porter’s better judgment eventually prevailed. According to reports, he determined that he had become an unnecessary distraction and submitted his resignation. Thus, more than 24 hours after providing a statement in support of Porter on the record, Kelly issued another statement condemning him. “I was shocked by the new allegations released today against Rob Porter,” the new dispatch read. “There is no place for domestic violence in our society.”

Only the kind of tunnel vision typical of life in the bunker can explain the nearsightedness that led the White House to think it could cover up a scandal like this and then weather the storm once it was exposed. Only if you have convinced yourself that your critics are beyond reason would you fail to see the obvious pitfalls associated with circling the wagons around an alleged serial abuser. John Kelly brought order to a chaotic West Wing. He’s an honorable figure who imposed sobriety on an atmosphere that was freewheeling and unserious. But he, too, succumbed to the myopia with which everyone with a siege mentality suffers.

The political impact of this debacle might not be short-lived. John Kelly’s position is in jeopardy. His resignation would suit those in Trump’s orbit who want to see a return to those early chaotic days of the administration. The Republican Party, too, has suffered a terrible setback. Democrats argued in bad faith that the GOP tacitly supported abusing women when some Republican senators opposed the Violence Against Women Act in 2013 because, among other things, it encouraged local police responding to a domestic disturbance call to make a “mandatory arrest” of someone—anyone—and flirted with unconstitutionality by allowing non-Native Americans accused of assault to be tried in tribal courts. Today, Democrats no longer have to stretch so hard to make the “anti-women” accusations stick.

The wagon-circling around Porter is a familiar sort of corruption. It’s the same impulse that led Trump’s allies to back former Alabama Senate candidate Roy Moore against his many accusers because, in the words of Breitbart’s Alex Marlow, to fail to do so would “create a standard” of acceptable conduct with women that Trump himself could not match. It’s the same degeneracy that led the president to wrestle with how forcefully to condemn violent white supremacists because some of them might have been his white supremacists. It’s the same brazen wantonness that leads respectable Republicans to chase flimsy conspiracy theories down rabbit holes, sacrificing invaluable credibility and transforming their constituents into fevered paranoiacs in the process.

The affair involving Rob Porter is only a symptom of a malady afflicting the Republican Party. As long as it is dug in with Donald Trump in the bunker, these unforced errors will continue and the GOP will suffer as a result.