The 45th president of the United States is a virus. He has infected America's body politic. And there's only one cure.

The particular form of this virus is really the most disturbing part of Donald Trump's presidency: the way his words and behavior constitute an ongoing and virulent assault on the very idea that institutions can rise above partisan politics to stand for the good of the nation as a whole.

Of course Democrats oppose President Trump and the agenda of his party. That's politics. But Trump doesn't limit his rhetorical wrath to Democratic politicians. In fact, if we set aside the president's peculiar obsession with the ghost of Hillary Clinton's presidential campaign, he devotes far more time and energy to railing against institutions and individuals that strive to rise above the partisan fray, to take their stand in the name of the public good: journalists, members of the intelligence community, and those who work in federal law enforcement.

It is America's faith in these institutions that the Trump virus has most worringly infected.

Behind the furious denunciation in public speeches and tweets is a consistent, implicit message on the part of the president: Those who claim to speak for the public good are lying. They're just concealing their political agenda, their angle. It's a pose, a ruse, a cover for their lust for power, a strategy that they deploy to give themselves a political advantage over those (like Trump himself) whose political ambitions are obvious and undeniable.

The president's most passionate defenders back him up by highlighting and hyping every example, however trivial, of an ostensibly nonpartisan actor displaying signs of anti-Trump bias, double standards, or exaggeration. See, this supposedly nonpolitical person is actually just a liberal Democrat out to bring down the president! It's nothing less than a coup!

This is how the virus spreads.

The truth, of course, is that our country's extra-partisan public institutions are doing exactly what they are supposed to do — attempting, as best they can, to contain and neutralize a potent and dangerous threat to the body politic. And make no mistake: the man (barely) elected president last November is just such a threat — a political virus spreading a contagion of flagrant corruption and lack of trust throughout the political system and culture.

There is only one cure for this virus. And it is for America's institutions to continue holding our president to account.

This doesn't mean that the members of America's extra-political institutions always do their jobs perfectly. Of course they don't. They're human. They set standards, strive to meet them, and often fall short. This will happen even more than usual in times of intense pressure and stress, when established civic norms and traditions are under continual, unprecedented assault. Overreaction is a constant temptation in such circumstances, as is sloppiness, as well as mistakes in judgment.

But this is our body politic at the present moment: feverish, achy, its antibodies fighting an invading virus using any means available — means that sometimes make the symptoms more severe. Members of the intelligence community who leak to the press are committing criminal acts. Journalists who publish those leaks run the risk of acting irresponsibly or appearing biased against the person who comes off looking bad in the resulting story. Reporters who tweet expressions of their own political fears and anger, not to mention those who tweet unverified rumors, undermine the trustworthiness of media.

All of this is bad, and it's certainly acceptable to call it out for criticism when it happens — so that it doesn't become the new, and far lower, normal. But it is still indisputably better than the alternative, which would be for the nation's extra-political public institutions to let Trump get away with flagrantly unpresidential behavior. In doing so, these institutions would be allowing the Trump virus to spread further into our body politic.

In the end, the antibodies may fail — America's compromised immune system may prove too fragile to defeat the virus. But still we need to try. Even when all the options are bad, some are better than others.