If in fact Trump Tower was wiretapped during the 2016 presidential campaign, as President Trump claimed in several tweets Saturday morning, he can do much more than say so on twitter: Presidents have the power to declassify anything at any time, so Trump could immediately make public any government records of such surveillance.

What Trump is saying seems to be a garbled version of previous reporting by the BBC, among other news outlets.

Terrible! Just found out that Obama had my “wires tapped” in Trump Tower just before the victory. Nothing found. This is McCarthyism!

Is it legal for a sitting President to be “wire tapping” a race for president prior to an election? Turned down by court earlier. A NEW LOW!

According to a report in the BBC, citing unnamed sources, a joint government task force was formed in spring of 2016 to look into an intelligence report from a foreign government that Russian money was somehow coming into the U.S. presidential race. In June the Department of Justice, part of the task force, asked the Foreign Intelligence Surveillance Act court for a warrant to intercept electronic communications by two Russian banks.

However, the BBC’s report says, the FISA court turned the application down.. The Justice Department then asked again in July with a more narrowly drawn request, which was again turned down. Justice then made a third request for a warrant on October 15, which was granted.

None of this involves wiretapping Trump Tower. However, it is possible that Trump picked that up from a Breitbart article that in turn relied on a Heat Street piece that claimed the warrant was issued because of evidence of links between a “private server in Donald Trump’s Trump Tower” and a Russian bank. In fact, the server in question, set up by a marketing company hired by Trump, was physically located in Philadelphia.

Barack Obama’s spokesman responded to Trump’s tweets by saying that “neither President Obama nor any White House official ever ordered surveillance on any U.S. citizen.” Notably, this statement does not deny that someone in the Obama administration ordered surveillance of Trump Tower, simply that the White House did not – which isn’t meaningful, since in a properly functioning executive branch the Justice Department would make that decision on its own without White House interference.

So what does all this mean?

The most likely explanation is that there was never any wiretapping of Trump Tower – or as Trump put it in another tweet, “my phones” — but the FISA court did allow surveillance of the Philadelphia server and the Justice Department ultimately decided there was nothing to it.

Or perhaps the Justice Department decided there was something to it and is still investigating it.

Or perhaps there were FISA court warrants but for surveillance of people around Trump that had nothing to do with the Philadelphia server and the Russian bank.

Or perhaps Trump never read the Breitbart article but instead learned there was significant surveillance of Trump Tower in the way you’d expect a president would, from the massive intelligence apparatus he commands.

Or perhaps Trump has simply gotten all of this wrong.

Whatever the case, Trump has the power to clarify it and everything else about the Russia story right now by declassifying whatever surveillance records exist of contacts between people in his orbit and Russia. If he and his associates did nothing wrong, he has every incentive to do so as soon as possible.

The White House press office did not immediately respond to requests to comment on whether Trump will use his declassification power regarding his tweeted claims. It’s previously ignored repeated questions about whether he will use it regarding the general issue of contacts between Russia and his campaign.

Interestingly, there has in fact been significant government surveillance involving a presidential campaign in the past, although it’s unlikely Trump will want to remind America of it.

During the 1968 contest between Hubert Humphrey and Richard Nixon, President Lyndon Johnson was attempting to negotiate a peace deal to end the Vietnam War.

Nixon was worried that if this happened just before the election it would help Humphrey, who was Johnson’s vice president. Recently discovered notes by one of Nixon’s top campaign aides show that Nixon asked him to “monkey wrench” the peace talks. Via Anna Chennault, a top Republican fundraiser, the Nixon campaign sent messages to the government of South Vietnam not to go along with Johnson’s plans.

Johnson knew that this was happening at the time, and believed that it constituted “treason.” He ordered the FBI to wiretap the embassy of South Vietnam in Washington, which picked up Ambassador Bui Diem communicating with Chennault. (Presidents could and did directly order wiretaps prior to the establishment of the FISA court in 1978 to prevent executive branch abuses of its surveillance power.) The FBI also began conducting general surveillance of Chennault.

Johnson and several top officials, including Secretary of Defense Clark Clifford and Secretary of State Dean Rusk, struggled with what to do in a fascinating phone call on November 4, 1968, the day before the election.

Johnson speaks of not wanting to be “a McCarthy” and worries about the certainty that “we’ll be charged with trying to interfere with the election.”

Rusk also equivocates, telling Johnson that “I do not believe that any president can make any use of interceptions or telephone taps in any way that would involve politics. The moment we cross over that divide we are in a different kind of society. … We get a lot of information through these special channels that we don’t make public. For example, some of the malfeasances of senators and congressmen and other people. … I think that we must continue to respect the classification of that kind of material.”

Clifford chimes in with another concern: that Americans just couldn’t endure learning how the world actually works. “I think,” Clifford frets, “that some elements of the story are so shocking in their nature that I’m wondering whether it would be good for the country to disclose the story, and then possibly to have a certain individual elected. It could cast his whole administration under such doubts that I would think it would be inimical to our country’s interests.”

In the end, Johnson decided not to reveal what he knew about Nixon’s shocking subterfuge.

The next day Nixon narrowly beat Humphrey. During Nixon’s time in office, 20,000 more U.S. soldiers and hundreds of thousands of Vietnamese died before the war finally ended.

The fact that Nixon did ally with a foreign government for advantage in a presidential election certainly doesn’t mean that Trump did the same. However, it does mean that U.S. politicians are capable of doing that – and that past presidents have used wiretaps to track the actions of their political adversaries.