There’s a lot still unknown about the informant, as The Washington Post explains: “It is unclear how he first became involved in the case, the extent of the information he provided and the actions he took to obtain intelligence for the FBI. It is also unknown whether his July 2016 interaction with Page was brokered by the FBI or another intelligence agency.”

That lack of detail has not stopped the president from leaping on the story—indeed, the vagueness has enabled him to make some strong charges:

Reports are there was indeed at least one FBI representative implanted, for political purposes, into my campaign for president. It took place very early on, and long before the phony Russia Hoax became a “hot” Fake News story. If true - all time biggest political scandal! — Donald J. Trump (@realDonaldTrump) May 18, 2018

If the FBI or DOJ was infiltrating a campaign for the benefit of another campaign, that is a really big deal. Only the release or review of documents that the House Intelligence Committee (also, Senate Judiciary) is asking for can give the conclusive answers. Drain the Swamp! — Donald J. Trump (@realDonaldTrump) May 19, 2018

Indeed, if the FBI or DOJ were infiltrating a campaign for the benefit of another, or for other “political purposes,” that would indeed be huge—along the lines of Watergate, as Trump has argued. So far, there is not evidence to back that up.

Hoping to solve that problem, Trump in a tweet on Sunday demanded a DOJ inquiry into “whether or not the FBI/DOJ infiltrated or surveilled the Trump Campaign for Political Purposes.” Note the turn here: Trump first declared that there was political interference in his campaign, and only second asked for a probe to figure out whether there was political interference in the campaign.

In a rational world, the fact that Trump advisers were in questionable contact with Russians; the fact that federal judges approved surveillance of Page and others; and the multiple indictments and guilty pleas that Mueller has already obtained, just a year into his investigation, would be the dominant story, since it indicates at the very least Russian tampering with the campaign and at the worst willing cooperation between campaign staffers and the Kremlin. The fact that several advisers were so quick to speak to the informant raises questions about vetting and information security on the Trump campaign.

Nor does it make sense that President Obama would have launched a legally and politically risky campaign to interfere with Trump, only to allow Trump to win the election in November.

There is also an irony to Trump politically interfering with the Justice Department to demand an investigation into political interference. (Ben Wittes writes in detail on the request and the dangers that it entails.) But because Trump is perfectly willing to politically interfere with the Justice Department, he seems to assume that his predecessors would have done the same.