It will be some time before we can evaluate the evidence that prompted the inspector general of the Department of Justice to conclude that Andrew McCabe, the deputy director of the FBI, had exhibited a "lack of candor" about his role in authorizing two FBI officials to speak to the media.

On its face, it is a serious charge brought by one highly respected professional — Michael Horowitz, the inspector general of the DOJ — against another, McCabe, who denies it adamantly.

It seems likely in the end that the evidence will allow conflicting interpretations. Nothing in McCabe's distinguished career suggests he would tell a bald lie; nothing in Horowitz's suggests he would concoct a smear.

But even if McCabe's transgression turns out to have been clear-cut, it won't matter.

It won't matter because the inspector general's conclusion, and the Office of Professional Responsibility's subsequent recommendation that McCabe be fired, doesn't justify the precooked decision of Attorney General Jeff Sessions to sack McCabe last Friday, just hours before McCabe's pension for 21 years of service to the country was due to vest.

That wasn't unlucky timing; it was the whole point of a politicized and vindictive campaign against the FBI and McCabe run from the top, and it represents a radical departure from conventional practice. The firing was a naked political hit.

Compare McCabe's fate with that of John Yoo, co-author of the George W. Bush administration "torture memos." Yoo was at least as controversial on the left as McCabe has come to be on the right. At the final stage of the internal review of his actions, Yoo was permitted several months to file a long brief in his own defense. McCabe, by contrast, was not even permitted to see the inspector general's final report, or the evidence on which it was based, until a week ago. He was given only four days to prepare a response. He delivered it Thursday. About 24 hours later, the ax fell.

The whole affair capped a year-plus of venomous Trump tweets about McCabe, including bratty schoolboy taunts about whether he would get to keep his pension and one calling his wife a loser.

More offensive still, Trump the petty dictator took again to the tweet-waves after the firing to call it "a great day for the hardworking men and women of the FBI — A great day for Democracy."

Rarely has Trump seemed so villainous, and so small.

McCabe figures to come out of the episode changed but intact. He likely will get his pension or the equivalent, one way or another. And he has signaled, perhaps surprisingly, that he intends to publicly take the fight to the president.

But even if the blow against McCabe is softened, Trump, abetted by Sessions (whose own job is on the line), has gained a greater foothold in his campaign to undermine the independence of federal law enforcement. This episode is terrifying because it suggests that Trump is making headway in his efforts to demonize the DOJ and FBI.

Both McCabe and the Trump camp have been quick to connect the sacking to something else: the inquiry by special counsel Robert S. Mueller III.

McCabe wrote in his statement that the administration's campaign against the FBI "only highlights the importance of the Special Counsel's work." And he said he believes that he was singled out both as retribution for his corroboration of the account of former FBI Director James Comey and to make him a less effective witness in an eventual trial or impeachment proceeding.

Trump has drawn the connection even more expressly. First, his personal lawyer put out an obviously orchestrated statement Saturday urging Deputy Attorney General Rod Rosenstein to "follow the brilliant and courageous example" of Sessions et al. in firing McCabe and shut down the Mueller investigation. And in a tweet salvo Sunday, Trump went strongly on the offensive, calling out Mueller by name for the first time and trashing the inquiry from multiple directions.

The McCabe railroading, grotesque in itself, heightens the stakes of the Mueller investigation. It represents the strongest strike yet in Trump's overall assault on independent, apolitical law enforcement, an indispensable feature of our democracy. It now seems clear that the lovers of justice and the rule of law are at war with a vicious band of villains. And it is at this point an unresolved and furious fight.

Harry Litman, a former U.S. attorney and deputy assistant attorney general, teaches at the University of California, San Diego, school of political science and practices law at Constantine Cannon. He wrote this article for the Los Angeles Times.