It all depends on the meaning of the word “investigation.”

That, apparently, is where we are in the constant debate about President Trump, Robert Mueller and the prosecutorial machinery clanking into action.

It seems to me largely semantics, but the is-he-or-isn’t-he argument stems from the latest push by the White House.

Jay Sekulow, a conservative attorney who is now a member of Trump’s legal team, has emerged as the president’s chief television defender. And in blitzing four Sunday shows, he mounted the argument that the special counsel is not investigating Trump.

Which would seem to be at odds with the president’s Friday tweet:

“I am being investigated for firing the FBI Director by the man who told me to fire the FBI Director! Witch Hunt.” (That was a swipe at his own deputy attorney general, Rod Rosenstein, who both wrote the fire-Jim-Comey memo—though Trump was already planning to do so—and named Mueller as special counsel.)

But in his contentious Sunday interviews, Sekulow said the tweet had been misinterpreted.

Here’s what he told Chris Wallace: “That tweet, Chris, was in response to the Washington Post story that alleged that five unnamed sources, anonymous sources, leaked to the Washington Post that the president was, in fact, under investigation. So that tweet was in response to that. There's been no notification of an investigation. Nothing's changed since James Comey said the president was not a target or subject of investigation. Nothing's changed."

Wallace was quite surprised, since Sekulow himself had twice referred to the president being under investigation. What followed was one of the most contentious interviews I’ve seen on “Fox News Sunday”:

"Here's what you're trying to do, Chris," Sekulow said.

"Now you're reading minds again," Wallace said.

"No, Chris, I deal with fact and law," Sekulow said. "You're asking me to read people's minds."

Sekulow pressed the same points with Chuck Todd, Jake Tapper and John Dickerson, telling Todd that the Washington Post story was “a fake report—a report with no documented sources.”

But no one has denied the substance of the Post story. The paper said that Mueller had arranged interviews with two top intelligence officials, Dan Coats and Mike Rogers, to ask about previous reports that Trump asked them to intervene with Comey’s investigation, and that they refused.

That would amount to looking into Trump’s actions on potential grounds of obstructing justice.

Sekulow clashed again yesterday with CNN’s Chris Cuomo, who said the lawyer could just make a phone call to find out whether his client is under investigation or not.

It is true that Mueller hasn’t said he is investigating Trump and hasn’t notified the president’s lawyers that he is under investigation. It is also true that Trump isn’t the subject or target of the probe. We’re still at a preliminary phase. And there’s still no evidence of what was supposed to be the point of the probe, collusion with Russia.

But I’m a bit mystified that the president would have one of his lawyers get into an endless back-and-forth over whether he is officially under investigation. At times it sounded like Bill Clinton debating the meaning of the word “is.” And Trump’s own tweet seemed to concede the point last week.

It might make more sense to argue that the president didn’t do anything wrong or that the investigation is straying far from its original mandate. Mueller and the prosecutors he has hired so far are clearly looking in part at Trump’s conduct. We may not know for some time whether they find anything.