WASHINGTON >> The Justice Department’s internal watchdog was caught in a political tug of war today as Republican and Democratic senators used his report on the origins of Russia investigation to back their views that it was an important and legitimate probe or a badly bungled farce.

Inspector General Michael Horowitz testified before the Senate Judiciary Committee about his findings this week that while the FBI had a legitimate basis to launch the Russia investigation and was not motivated by political bias in doing so, there were major flaws in how that investigation was conducted.

The hearing was the latest reflection of Washington’s intense politicization. Senators from both parties praised a detailed, nuanced report by a widely respected, nonpartisan investigator, while pressing him to call attention to findings that back their positions.

Horowitz tried to strike a balance. He insisted that the FBI should not feel comforted by his findings and pointed out the absence of evidence for some of the most sensational claims by President Donald Trump and his supporters: that the investigation into ties between his 2016 campaign and Russia had been opened for political reasons or that agents had infiltrated his election bid.

His opening statement was overwhelmingly critical of the investigation, focusing more on the flaws that his report. Under questioning from Republicans, he rejected the views of former FBI Director James Comey, who had claimed vindication for the bureau based on Horowitz’s conclusions.

“I think the activities we found don’t vindicate anybody” in the FBI involved in preparing applications to eavesdrop on a former Trump campaign aide.

Yet Horowitz also repeatedly noted under questioning from Democrats that he had not found that the FBI had targeted Trump for investigation for political reasons.

“It finds that it was a properly predicated investigation based on the rules on the FBI,” Horowitz of his report.

Trump and his supporters are counting on different conclusions from a separate investigation led by John Durham, a prosecutor selected by Attorney General William Barr to investigate the early days of the Russia investigation. Durham issued a statement disputing some of Horowitz’s conclusions. But Horowitz said they had a relatively technical disagreement — that the evidence was sufficient to open a preliminary investigation but not a full one. The latter gives the FBI more intrusive tools for an investigation.

Horowitz’s report identified significant problems with applications to receive and renew warrants to eavesdrop on former Trump campaign aide Carter Page in 2016 and 2017. Investigators were concerned about Page’s ties to Russia, but never accused him of wrongdoing.

Horowitz told senators that the FBI failed to follow its own standards for accuracy and completeness when it sought a warrant from the secretive Foreign Intelligence Surveillance Court to monitor Page’s communications.

The report detailed 17 errors and omissions during those wiretap applications, including failing to tell the court when questions about raised about the reliability of some of the information that it had presented to receive the warrants.

“We are deeply concerned that so many basic and fundamental errors were made by three separate, hand-picked investigative teams, on one of the most sensitive FBI investigations, after the matter had been briefed to the highest levels within the FBI,” Horowitz said.

Those problems were especially alarming because the warrant to monitor Page “related so closely to an ongoing presidential campaign” and “even though those involved with the investigation knew that their actions were likely to be subjected to close scrutiny.”

Horowitz’s findings that the FBI was justified in launching the investigation has been criticized by Barr, a vocal Trump defender. On Tuesday, Barr said the Russia investigation was based on a “bogus narrative” and he declined to rule out that agents may have acted in bad faith.

Horowitz said that he has spoken with Barr about his findings, and that the attorney general did not present anything that changed his conclusions.

Republican senators repeatedly asked about another criticism Horowitz leveled at the FBI — that the bureau sent a representative from its Russia investigation team to a strategic intelligence briefing that intelligence officials gave to both the Hillary Clinton and Trump campaigns, including to Trump himself and aide Michael Flynn, who later became the administration’s national security adviser.

That was a “pretext,” Horowitz said, to collect information that might be relevant for the investigation. The FBI debated but ultimately opted to not give a standard and more extensive defensive briefing that Russia might be trying to influence their campaign, fearful that it could impede the ongoing counterintelligence investigation.

Sen. Sheldon Whitehouse, D-R.I., said that decision struck him as reasonable, particularly because Flynn was himself under suspicion and ultimately pleaded guilty to lying to the FBI about his interactions with Russia’s ambassador to the United States.

Nonetheless, Horowitz said, “it raises significant policy questions.”

In a blistering opening statement, the committee chairman, GOP Sen. Lindsey Graham of South Carolina, said the code name for the FBI investigation, “Crossfire Hurricane,” was an apt title “because that’s what we ended up with — a ‘Crossfire Hurricane.’”

“What happened here is the system failed. People in the highest levels of government took the law into their own hands,” said Graham, a close Trump ally.

Sen. Dianne Feinstein of California, the committee’s top Democrat, said, “I believe strongly that it’s time to move on from the false claims of political bias.”