WASHINGTON — President Donald Trump wasted no time before seizing on last week’s report by the Justice Department’s internal watchdog on misconduct allegations against the FBI’s former No. 2 official, Andrew McCabe. Trump tweeted it was proof that his archrival James Comey, the former FBI director, “totally controlled” McCabe.

But the report by Inspector General Michael Horowitz said no such thing. In fact, it depicted clashing accounts of a conversation they had that contributed to McCabe’s dismissal.

It wasn’t unusual for Horowitz to see his actions — or his own credibility — caught up in Washington’s political storms, despite the apolitical reputation he has cultivated over six years on the job. Trump has disparagingly called Horowitz an “Obama guy” even as McCabe’s lawyers have decried the report and investigative process as unfair. No matter the opinion, there’s no doubting the impact of the work: It helped lay the groundwork for McCabe’s firing and opened him to torrential criticism by Trump and his supporters.

The controversies he has endured are likely nothing compared to what awaits him in coming weeks when he announces the findings of his review into the FBI’s handling of the Hillary Clinton email investigation. The report will inflame the debate about whether FBI actions during the campaign affected the race’s outcome. And Trump’s friends and foes will inevitably scour for any nugget that can undermine his criticism of their side, and Horowitz himself.

Charles McCullough, a former intelligence community inspector general who referred the Clinton emails to the FBI, said he believes Horowitz’s report will be “absolutely thorough and completely accurate.”