The war on former FBI Director James Comey has begun. And President Donald Trump himself fired the opening shot. On Twitter, Donald Trump introduced a new insult to his repertoire, calling James Comey a “slime ball.”

James Comey is a proven LEAKER & LIAR. Virtually everyone in Washington thought he should be fired for the terrible job he did-until he was, in fact, fired. He leaked CLASSIFIED information, for which he should be prosecuted. He lied to Congress under OATH. He is a weak and..... — Donald J. Trump (@realDonaldTrump) April 13, 2018

....untruthful slime ball who was, as time has proven, a terrible Director of the FBI. His handling of the Crooked Hillary Clinton case, and the events surrounding it, will go down as one of the worst “botch jobs” of history. It was my great honor to fire James Comey! — Donald J. Trump (@realDonaldTrump) April 13, 2018

Trump and his allies are trying to get out ahead of the release of Comey’s book next week, in which the former FBI head characterizes the president as a pee-tape-obsessed fantasist whose expectations of loyalty were reminiscent of Mafia dons.

The Republican National Committee and the White House have collaborated on a campaign to damage Comey’s credibility — and in the process to imply that Deputy Attorney General Rod Rosenstein and special counsel Robert Mueller, who are now overseeing the investigation into Russian collusion and obstruction of justice, are compromised by association with Comey.

True to form, Trump himself is leading the charge, and he’s doing it on Twitter.

Why Trump calls Comey a “liar” and a “leaker”

Donald Trump is mashing three different attacks on Comey into the space of 560 characters. Since they’re all complaints that Trump and his allies have made about Comey before, though, it’s pretty easy to figure out what the president means.

“Virtually everyone in Washington thought he should be fired” for “his handling of the Crooked Hillary Clinton case.” The official reason that Comey was fired, as spelled out in a memo from Rosenstein, was his handling of the FBI investigation into Hillary Clinton’s use of a private email server as secretary of state. But Rosenstein’s allegations — echoing criticisms made by Democrats during and after the 2016 presidential campaign — were that Comey had been unfair to Clinton.

In July 2016, Comey held a press conference to announce that no charges would be filed in the investigation, but nonetheless chided Clinton for her “extremely careless” email use. Democrats saw it as an attempt to imply wrongdoing on Clinton’s part even without a criminal charge.

Then, days before the election, Comey announced that the FBI was reopening the Clinton investigation to see if the FBI-seized laptop of former Rep. Anthony Weiner (D-NY), whose then-wife was a close Clinton adviser, held any new evidence. This, too, was seen as an irresponsible attempt to smear Clinton.

(In his book, Comey reportedly admits that he assumed at the time Clinton would be elected president and worried she’d be seen as “illegitimate” if it appeared the FBI had suppressed the investigation news — and that he’s not sure he would have done the same thing if he’d known Trump would win.)

Donald Trump ostensibly understands this, because it’s ostensibly the reason he had the “great honor” of firing Comey. And his comment that “virtually everyone in Washington” wanted Comey gone, like previous Trump remarks about Democrats hating Comey, shows he understands on some level what the real issue with Comey’s handling of the Clinton investigation was. But just from reading the tweet, with its reference to Comey’s “handling of the Crooked Hillary Clinton case,” you might well assume that Comey was fired for not charging Clinton with any crimes.

“He leaked CLASSIFIED information.” After he was fired, Comey testified before the Senate Intelligence Committee about his interactions with President Trump, telling them that Trump had asked Comey for “loyalty” before announcing he would keep him on as FBI head; that the president frequently asked the FBI director to tell the public that Trump himself was not under investigation in the Russia scandal; and that he’d expressed a hope that Comey would “see [his] way” to letting former National Security Adviser Michael Flynn off the hook in his criminal investigation.

Trump and his allies were furious at this disclosure, and at reports that Comey had taken notes of his meetings with Trump at the time and had shared them with colleagues at the FBI. They attempted to assert that Comey was breaking “executive privilege” by talking to the public or Congress about it. Trump himself went further, accusing Comey of “leaking” — and is now specifying he leaked “CLASSIFIED information.”

None of this holds up. Not every interaction with the president is automatically classified, and there’s no evidence to date that anything Comey has disclosed was officially considered classified. And unless something is classified, the White House doesn’t have control over what former officials say about it after they leave the White House.

“He lied to Congress UNDER OATH.” Trump has denied that he asked Comey to drop the Flynn investigation. If Trump is telling the truth, Comey did in fact perjure himself to the Senate by saying otherwise. But Trump does not exactly have a sterling record of telling the truth — and, of course, it’s easier for the person who isn’t under oath to lie about something. It’s also worth noting that the things Trump is accusing Comey of lying about are the exact same things he’s accusing him of “leaking.”

Many Trump tweets are impulsive. But this is part of a coordinated campaign to attack Comey.

Often, when Trump starts the day on Twitter, his proclamations come as a surprise to his advisers as much as anyone else. It’s become clear in recent weeks that Trump isn’t deferring to anyone anymore, and administration officials have often scrambled to justify whatever he just said.

This isn’t like that.

As my colleague Matt Yglesias wrote yesterday, the attacks on “Lyin’ Comey” are a premeditated and coordinated campaign, complete with a website. The Republican National Committee collaborated with White House staff to develop the messaging.

It’s not clear what role Trump himself played in this process, although, of course, the moniker “Lyin’ Comey” is Trump’s. And it’s unlikely that anyone needed to coach Trump to go after Comey on Twitter.

But the point is that the Comey saga is no longer at the point where White House staff feel the need to soften Trump’s attacks after the fact, or offer justifications for his animus. They’re all in. “Lyin’ Comey” is no longer a Donald Trump thing; it is now a Republican Party thing. The president’s Twitter account is just the tip of the spear.