There has been bitter debate about the release of a heavily-redacted version of the FBI's application for a Foreign Intelligence Surveillance Act warrant to wiretap onetime Trump foreign policy adviser Carter Page. The debate centers on whether the FBI gave the FISA court judges enough information to assess the anti-Trump motives of the people behind the Steele dossier.

[READ: All the declassified FISA documents on Carter Page]

House Intelligence Committee Chairman Devin Nunes, R-Calif., set off the argument last February, with the release of the so-called Nunes memo. In the memo, Nunes wrote, "Neither the initial application in October 2016, nor any of the renewals, disclose or reference the role of the DNC, Clinton campaign, or any party/campaign in funding Steele's efforts."

The release last weekend of blacked-out copies of the original application and three renewals confirmed Nunes' description; the documents did not mention the DNC or Clinton campaign's role in funding Steele. Nevertheless, defenders of the FBI's actions in this case argued that even if the FBI did not specifically include the words "Clinton campaign" or "DNC," the bureau fully informed the court that the people involved with the dossier had a political motive against candidate Donald Trump. To support their position, defenders pointed to a multi-paragraph footnote in the FISA application that contained this sentence: "The FBI speculates that the identified U.S. person was likely looking for information that could be used to discredit Candidate #1's campaign."

The "identified U.S. person" referred to Glenn Simpson, the Fusion GPS opposition researcher who recruited former British spy Christopher Steele to search for Russia-related dirt on Trump, who is referred to as "Candidate #1" in the application.

"The FBI gave the court enough information to evaluate Steele's credibility," former Justice Department official David Kris wrote on Lawfare. "The footnote disclosing Steele's possible bias takes up more than a full page in the applications, so there is literally no way the FISA court could have missed it."

But the footnote did not, in fact, disclose Steele's possible bias. It disclosed Simpson's possible bias. The FBI's disclosure of bias — "The FBI speculates" — referred specifically to the "identified U.S. person" who might have wanted to discredit the Trump campaign. That was Simpson, not Steele.

Indeed, a close reading of both the FISA application and the Nunes memo raises questions about whether the FBI told the judges anything about Steele's possible bias — even though the bureau had evidence that the former spy was out to get Trump.

In the initial and later applications, the FBI did not even hint that Steele, referred to as "Source #1" in the application, was biased against Trump. In fact, on more than one occasion, the FBI presented Steele, who had worked with the FBI in the world soccer corruption investigation a few years earlier, as a reliable source with no marks against his credibility.

"Source #1's reporting has been corroborated and used in criminal proceedings and the FBI assesses Source #1 to be reliable," the FBI wrote. "Source #1 has been compensated [REDACTED] by the FBI and the FBI is unaware of any derogatory information pertaining to Source #1."

In another part of the footnote, the FBI said Simpson "never advised Source #1 as to the motivation behind the research into Candidate #1's ties to Russia," suggesting Steele had no idea that his employers were trying to stop Trump.

In yet another part of the footnote, the bureau said "the FBI believes Source #1's reporting herein to be credible."

The problem for the FBI is this: The initial FISA application containing those footnotes was filed in October 2016. In the previous month, September, Steele told Justice Department official Bruce Ohr that he, Steele, was "desperate that Donald Trump not get elected and was passionate about him not being president," according to Ohr's account quoted in the Nunes memo. At the time of applying for the warrant, the Justice Department knew about Steele's "desperate" and "passionate" anti-Trumpism, but did not tell the court.

"This clear evidence of Steele's bias was recorded by Ohr at the time and subsequently in official FBI files — but not reflected in any of the Page FISA applications," Nunes wrote.

Senate Judiciary Committee Chairman Chuck Grassley, R-Iowa, corroborated Nunes' point, writing on Jan. 24, 2018, that Ohr "noted...that Mr. Steele was 'desperate' to see that Mr. Trump was not elected president. None of the information provided by Mr. Ohr in his interviews with the FBI was included in the FISA renewal applications."

It is generally accepted that evidence of a source's bias, including the source's own acknowledgment of it, should be disclosed in warrant applications that are predicated on that source. The FBI simply did not do that in Steele's case.

But perhaps the bureau, when it filed the first application in October, did not know what Steele had said to Ohr just the month before. Perhaps. The problem is, the FBI also failed to include the information in any of the later renewal applications, in January, April, and June of 2017.

The later applications did inform the court of problems with Steele. The FBI expected that Steele, as a trusted (and paid) source, would not share his findings with the press. Yet that is what Steele did in September and October before the election, when he discussed his work with reporters from the New York Times, Washington Post, CNN, New Yorker, Yahoo, and Mother Jones — and then falsely denied that he had.

In subsequent renewal applications, the FBI informed the court that it had suspended, and then ended, its relationship with Steele. But the bureau argued that Steele was still a reliable source, because he broke his agreement and lied after he gave the FBI the information included in the warrant application.

There might be one cautionary note here. In one of the footnotes in which the FBI vouched for Steele's reliability, the bureau put it this way: "Notwithstanding Source #1's reason for conducting the research into Candidate #1's ties to Russia, based on Source #1's previous reporting history with the FBI, whereby Source #1 provided reliable information to the FBI, the FBI believes Source #1's reporting herein to be credible." What does the "notwithstanding" clause mean? Does it mean the FBI did include information on Steele's "reason for conducting the research" somewhere in the FISA application that it is simply blacked out? That is, perhaps, possible, but there is no indication from the application or any of the other testimony and evidence in the case — certainly not from Nunes' and Grassley's accounts — to suggest that the FBI did.

In addition to Steele's "desperate" and "passionate" comments, there are other reports the FBI knew the former British spy had an anti-Trump agenda. In the book Russian Roulette, authors Michael Isikoff and David Corn — both of whom were briefed by Steele about his findings during the campaign — reported the FBI was aware of Steele's anti-Trump motivations.

FBI officials "knew from the outset that Steele had an agenda and that he was likely working for the Democrats," Isikoff and Corn wrote. "But this was not a deal breaker, according to one senior official who reviewed Steele's report at the time. FBI agents were used to receiving intelligence from informants with agendas or grudges."

The issue, of course, as far as the FISA application was concerned, was whether the FBI shared that knowledge with the court.

In another passage, Isikoff and Corn wrote: "As FBI officials saw it, Steele seemed more interested in getting the story out rather than quietly working with them on the investigation. 'There was clearly an agenda on his part,' one senior FBI official later said."

So to conclude: The FBI based a substantial part of its warrant application on Steele's work. Steele had a strong and clear anti-Trump bias. The FBI knew about it. The bureau should have informed the court. And it did not.