But would that be a valid claim for the White House to make?
Let's start with the wording of the claim, and take it piece by piece. Here's what Trump tweeted:
There are three elements here: 1) Trump's “wires” were “tapped”, 2) It happened at Trump Tower, and 3) Obama did it.
The first part is still unproven. If the CNN report is correct, there is still no indication that Trump himself was targeted by wiretapping; the report leaves open the possibility that a conversation with Trump may have been swept up in the Manafort tap, but we have no indication that it was.
The second part — the Trump Tower part — is also possibly true based on what CNN reported, though again we just don't know for sure. While Trump himself wasn't the reported target of the wiretap, Manafort did have an apartment at Trump Tower, so it's possible that location was, in fact, wiretapped.
As for the third part, on Obama, Trump's tweet again seems to claim more than CNN is reporting. FISA warrants require sign-off from top Justice Department and FBI officials, but Trump was suggesting that Obama was personally involved.
It's worth noting in all of this that Trump's own Justice Department has cast doubt on his claim. In a court filing earlier this month, it said flatly that, “Both FBI and [its national security division] confirm that they have no records related to wiretaps as described by the March 4, 2017 tweets.” Then-FBI Director James B. Comey also said back in March that there was no evidence to support the claims.
The last element of this that should raise some eyebrows is this:
The conversations between Manafort and Trump continued after the President took office, long after the FBI investigation into Manafort was publicly known, the sources told CNN. They went on until lawyers for the President and Manafort insisted that they stop, according to the sources.
If Trump's lawyers somehow knew about and fought back against the Manafort wiretap, it stands to reason that Trump himself might have been aware of it. A lingering question after Trump's March tweets was whether he, as president, knew something that the rest of us didn't. While we don't know the exact timing of all of this, perhaps this is what Trump was referring to and he, as he is wont to do, exaggerated it.
But even that explanation wouldn't make total sense. Shortly after Trump's tweets, both then-White House press secretary Sean Spicer and White House counselor Kellyanne Conway suggested he didn't literally mean “wiretapping.” “The president used the word 'wiretaps' in quotes to mean, broadly, surveillance and other activities,” Spicer said. Conway added that, “What I can say is there are many ways to surveil each other,” and she mentioned the possibility of doing so with both TVs and microwaves. So if Trump didn't literally mean wiretapping, CNN's Manafort story wouldn't be confirmation.
Overall, the fact remains that in more than six months since Trump tweeted them, both Trump and his Justice Department haven't produced any validation of his specific claims. If it exists, they are withholding it for completely unclear reasons.
Update: Comey's lawyer has responded to the report and subsequent suggestions that Comey's testimony might have been wrong. "I don’t believe Jim is aware of any information that would cause him to second guess or change his testimony,” said David N. Kelley.
Matt Zapotosky contributed to this post.