It's something the American people have been demanding for months — and Thursday it will finally be revealed.

The Justice Department's internal watchdog is expected to slam the FBI's handling of the Hillary Clinton email investigation, stepping into a political minefield while examining how a determinedly nonpartisan law enforcement agency got itself entangled in the 2016 presidential race.

The inspector general's report is set for release Thursday afternoon. It's likely to be painstakingly detailed, the culmination of an 18-month review into one of the most consequential FBI investigations in recent history.

President Donald Trump will look to the inspector general report to provide a fresh line of attack against two former top FBI officials, former Director James Comey and his deputy, Andrew McCabe, after a politically tainted bureau tried to undermine his campaign and, through the Russia investigation, his presidency. Trump will almost certainly use the report to validate his firing of Comey last year.

Inspector General Michael Horowitz, a former federal prosecutor appointed by President Barack Obama, prepared the report. Supporters from both parties regard him as apolitical. His most significant report before this one was the 2012 study of the major Obama-era scandal known as Fast and Furious.

The Clinton report will examine key actions by FBI leaders. People familiar with the report's findings say the inspector general is going to slam Comey and many other FBI officials. An earlier inspector general report criticized McCabe and led to his firing on allegations that he misled internal investigators about his role as a mainstream media leaker. He denies those charges.

Trump, seeking to discredit special counsel Robert Mueller's investigation, has eagerly awaited the report in hopes that it would skewer the judgment of Comey and make clear that his termination — central to the question of whether the president sought to obstruct justice — was justified.

The White House pointed to Comey's handling of the Clinton investigation as the rationale for the firing. Top Democrats had also called for Comey's ouster for months.

Trump has repeatedly lambasted the former FBI chiefs as politically biased against him, but the inspector general's report — no matter how critical — is unlikely to endorse that conclusion, especially since some of the actions being examined broke from protocol in ways that may have harmed Clinton.