Something dangerous has changed in Washington.

One of President Trump's personal lawyers, John Dowd, is now arguing publicly that a president can't be prosecuted for obstruction of justice because as the nation's chief law enforcement officer, the president decides what justice ought to be. In this case, the theory is that if Trump decides that his friend Mike Flynn should be immune from prosecution, as president he has the authority to make that happen and no one can interfere.

If Trump decides to shut down an entire criminal investigation into his own administration, even into his own actions, under Dowd's theory he can do that too, if necessary by firing the FBI director or presumably even the special counsel.

Another of Trump's personal lawyers, Jay Sekulow, makes a similar argument about possible collusion between the Trump campaign and Russian officials: Even if it happened, even if Trump knew about and welcomed Russian help in the election, there's nothing that anyone can or should do about it.

"For something to be a crime, there has to be a statute that you claim is being violated," as Sekulow told The New Yorker. "There is not a statute that refers to criminal collusion. There is no crime of collusion."

And of course, former Harvard law professor Alan Dershowitz is all over cable TV these days, bolstering both arguments on behalf of Trump, much to Trump's delight.

(As an aside, it is downright uncanny how often Dershowitz's carefully thought-through, scholarly legal analysis happen to coincide with the fondest desires of cable news bookers. It's one of those mysteries of the universe.)

In short, we are no longer debating whether collusion or obstruction of justice happened, but whether they are legal or whether something can be done about them. We are debating not the legitimacy of Trump's actions, but the legitimacy of the investigation into such matters. The legitimacy of the people and agencies conducting the investigation is also under all-out assault by the president and his supplicants.

It's pretty astonishing. We have a law-and-order president who in every other instance has cast himself as the stern defender of law enforcement, but in this instance is publicly attacking the integrity of the nation's pre-eminent law-enforcement agency. This comes after Trump has also attacked the legitimacy of the nation's top intelligence-gathering agencies.

And just so it's clear: We have absolutely zero evidence that Clinton lied to the FBI. There is no plausible, fact-based allegation that Clinton lied to the FBI. All we have are some conservatives who very much want to believe that Clinton lied to the FBI, and a president eager to make their wishes appear to be reality.

They still are not reality.

By this point, Trump has now appointed the head of the FBI, the CIA and the Justice Department, and he still cannot force them to do what he wants because what he wants is against the law. Even Attorney General Jeff Sessions has refused to open an investigation into Clinton, as Trump publicly demands, because he knows that he has no legal grounds on which to do so.

So far, in other words, the institutions of democracy are holding up. So far. But if you listen to the arguments being made and watch the pressures being exerted, both publicly and privately, you begin to realize that the real test of their structural soundness has yet to come, and it is likely to be seismic.