“I’ve taken the position — and I don’t have to take this position and maybe I’ll change — that I will not be involved with the Justice Department,” President Donald Trump said in an April 26 interview on Fox & Friends. And on Sunday, he changed his mind. The president of the United States said on Twitter that he will demand that the Department of Justice investigate whether the department or the FBI “infiltrated or surveilled” his presidential campaign for political purposes and if any such requests were made by the Obama administration.

The tweet appears to be a reaction to a pair of reports from the New York Times and the Washington Post this week that the FBI sent an informant to talk to Trump campaign advisers after the bureau found evidence the campaign had suspicious contacts with Russia in the early stages of the Russia investigation. The informant, an academic who both publications declined to identify, made contact with George Papadopoulos and Carter Page and, according to the Post, Sam Clovis in 2016. Trump and his allies have falsely claimed the informant was a “spy.”

I hereby demand, and will do so officially tomorrow, that the Department of Justice look into whether or not the FBI/DOJ infiltrated or surveilled the Trump Campaign for Political Purposes - and if any such demands or requests were made by people within the Obama Administration! — Donald J. Trump (@realDonaldTrump) May 20, 2018

The Trump-Russia investigation originated with Papadopoulos, who drunkenly bragged about being approached by a Russian-linked professor who said the Kremlin had dirt on Hillary Clinton to an Australian diplomat in May 2016. The diplomat later tipped off the United States to Papadopoulos’ comments. Papadopoulos has since pleaded guilty to making false statements to the FBI as part of Robert Mueller’s investigation into Russian meddling in the 2016 election and potential collusion between the Trump campaign and Russia. Page was legally surveilled by the FBI for almost a year starting in October 2016 because of his Russia contacts.

Trump and his allies have cried foul. Trump tweeted on Thursday if there was an informant on his campaign, it would be “bigger than Watergate.”

“If they did this, if there was a plant, if there was a spy, if there was an informant put in the other party’s campaign during the election, that is as wrong as it gets,” Rep. Jim Jordan (R-OH) said in an appearance on Fox News on Friday.

But as the Times notes, there is no evidence that the informant was a secret spy sent to infiltrate the Trump campaign, as Trump and his allies claim. More likely: Investigators were trying to figure out just what was going on between these Trump guys and Russia.

“The notion of fully embedded government operatives inside a campaign is hard to imagine under these circumstances,” said Frank Figliuzzi, a former head of FBI counterintelligence, to NBC News. “What is easier to imagine is the FBI trying to flesh out information on Russian intelligence operatives by making approaches to campaign staffers if the reasonable suspicion was there and the approvals were in place.”

This is a big deal

Trump has the Constitutional authority to make the demand he previewed on Sunday, but there are a couple of things to keep in mind here. For one thing, the Justice Department’s inspector general launched an investigation into how the FBI got permission to spy on Page in March, so part of what Trump is asking for is already happening. And while it’s not clear whether anything the FBI, DOJ, or Obama administration did regarding the 2016 campaign was politically motivated, Trump’s call for a probe on Sunday certainly is.

The president’s demand, should he go through with it, could set up a showdown between Trump and the Justice Department officials expected to execute it. Carrie Cordero, an adjunct professor at Georgetown University, pointed out on Twitter that the Justice Department doesn’t open investigations for political purposes. “There are rules. And I’m convinced there are people left in this government who will follow them,” she wrote.

Justice Department spokeswoman Sarah Isgur Flores said in an emailed statement that the Justice Department has asked the inspector general to expand the ongoing review of the Page application to “include whether there was any impropriety or political motivation in how the FBI conducted its counterintelligence investigation of persons suspected of involvement with the Russian agents who interfered in the 2016 presidential election.”

Deputy Attorney General Rod Rosenstein released a separate statement responding to Trump. “If anyone did infiltrate or surveil participants in a presidential campaign for inappropriate purposes, we need to know about it and take appropriate action,” he said.

Trump has spent much of the day on Sunday publicly raging on Twitter about the Mueller investigation and its expansiveness. He has repeatedly decried it as a “witch hunt,” wondering openly about when it will stop. The president’s paranoia, susceptibility to conspiracy, and apparent desire to deter and meddle in the Mueller investigation are becoming increasingly disturbing.

Update: Updated with statements from the Department of Justice and Deputy Attorney General Rod Rosenstein.