“The great irony here is that no one’s actually disputing the core allegation in the application,” Mr. Vladeck said in interview, “which is that there was at least probable cause to believe Carter Page was working as an agent of a foreign power.”
In his tweets, the president, Mr. Vladeck said, also seemed to be shifting the focus of his criticism from the F.B.I. to the Foreign Intelligence Surveillance Court. Warrant applications, generated at early stages of an investigation, tend to be “one-sided,” Mr. Vladeck said, and officials may not be telling the court every single thing they know when filing them.
“He’s focusing on the imperfections of the application, of which there are many because these documents tend not to be perfect,” Mr. Vladeck said. “Out of context, these individual imperfections may look a lot more sinister.”
But, he added, the application still contained “a substantial amount of information provided to four different Republican-appointed FISA court judges who established probable cause.”
While Mr. Trump did not elaborate on Sunday on why he felt that the FISA application had proved his accusations, he had claimed similar vindication in February when he endorsed highly contentious accusations by Republicans on the House Intelligence Committee that the F.B.I. had misused its surveillance powers in the Page case.
A memo issued at the time by Republicans on the committee drew on information in the surveillance documents, though Democrats said the Republicans made distorted claims to protect Mr. Trump and try to undermine the Russia inquiry. That memo, like the documents released on Saturday, did nothing to clear Mr. Trump of either collusion or obstruction, the lines of inquiry being pursued by the special counsel.
In the nearly two years since the initial application was filed, Mr. Page, a former foreign policy adviser to the Trump campaign, has has not been charged with any crime. And as Mr. Trump and some Republican lawmakers persistently deplore the special counsel’s investigation into Russian election inference as a “witch hunt,” the wiretapping of Mr. Page has emerged as an opportunity to sow doubt about the motives of the investigation.