History matters, especially when an unscrupulous president constantly seeks to revise and distort fundamental facts as events unfold. This week, a courageous law enforcement official stepped forward to correct the record at last, and under oath.

Over the past two years, as the Russia and Ukraine investigations unfolded, President Donald Trump has tried repeatedly to turn the expanding indictment of his own criminal misconduct into a case against his political adversaries. "Treason!" he tweets every few days, punctuating his outlandish claim that the investigations of sleazy and potentially unlawful behavior by him, members of his family, his campaign aides and his appointees represented a nefarious "deep state" conspiracy.

Although Trump himself lacks any capacity to articulate these absurdities — let alone prove them — the usual suspects at Fox News Channel and on Capitol Hill have spent many hours fabricating a narrative (while occasionally fabricating "proof," too). They claim that the original investigation of the Trump campaign's ties to Russia was illegitimate, as was the stunning indictment of national security adviser Michael Flynn during the new administration's early days.

Republican lawmakers have promoted those same themes to deflect attention from the Trump administration's offenses and failures, with Sen. Lindsey Graham (R-SC), perverting the Senate Judiciary Committee he chairs for that purpose. In his zeal to promote conspiracy theories, however, Graham made the mistake of calling former Deputy Attorney General Sally Yates to testify on Wednesday.

Yates, who also served as acting attorney general, turned out to be a devastating witness whose sworn account coolly debunked the Trumpian fantasies on every point.

In countless tweets, Trump has accused former President Barack Obama of "spying" on him and his associates both during and after the election. It's the greatest scandal in American history, worse than Watergate, et cetera, et cetera! But Yates pointed out that neither Trump nor any of his aides was ever wiretapped or surveilled. Instead, the Justice Department was conducting a counterintelligence operation that targeted Russian Ambassador to the U.S. Sergey Kislyak.

That was how the FBI discovered and recorded Flynn's perfidious contacts with the Kremlin.

What Yates and her fellow prosecutors learned from those recordings was that the former general (once famously entertained by Russian President Vladimir Putin himself) had undermined U.S. sanctions imposed after Russia intervened in the 2016 presidential election. Those same recordings later showed that Flynn had deceived Vice President Mike Pence and other officials about his contacts with Russia. She testified that the probe continued because of the revelations about Flynn's subversion.

There was no attempt by the Obama administration — including then-Vice President Joe Biden — to direct the investigation to harm Trump or his incoming administration, she said. There was no effort to interfere with Trump's campaign using a falsified intelligence warrant. Such claims barely merit discussion, since it was Hillary Clinton's campaign, not Donald Trump's, that was undone by the public revelations about an FBI investigation.

Having established the basic facts, Yates bluntly rebuked the machinations by Attorney General William Barr to protect Flynn from the consequences of his acts — which have enraged and embarrassed nearly every lawyer who ever served the United States. She contradicted Barr's weak claims exonerating Flynn of lying to the FBI, which the attorney general used to dismiss his guilty plea. And Yates didn't hesitate to point out the terrible consequences for the integrity of the justice system when the highest law enforcement officer uses his power to rescue the president's guilty accomplices.

Covering Yates' testimony, the Washington Post's Jennifer Rubin described Sally Yates as a straight professional, free of partisan taint — in short, the opposite of the badly bent Bill Barr. When Trump and Barr and their ilk are at last gone, it will be figures of integrity like Yates who restore the rule of law and repair the depredations of this regime.

To find out more about Joe Conason and read features by other Creators Syndicate writers and cartoonists, visit the Creators Syndicate website at www.creators.com.