Are you not entertained? That disdainful line from "Gladiator" came to mind watching Democrats and Republicans maul each other Wednesday over Michael Cohen's long denunciation of Donald J. Trump. The day proved again that Mr. Trump has associated with some dreadful characters, and has no great character himself, but Democrats will need more than the testimony of a former fixer to impeach him.

Mr. Cohen spared no nasty noun in describing the mogul turned President he served — blindly he now says — for 10 years. "Con man," "racist" and "cheat" were highlights, as Mr. Cohen unburdened himself of what he called a decade of lies. He admitted lying for years to protect Mr. Trump, including to Congress, though he now says he's telling the truth to ruin him. He will soon serve a three-year sentence for his crimes, most unrelated to Mr. Trump.

The day was above all a reminder that Americans elected a President in 2016 who had spent decades in the sleazier corners of New York business and tabloid life.

Histrionics aside, the hearing revealed few new details. The most potentially damaging was Mr. Cohen's disclosure that Mr. Trump knew in advance about the WikiLeaks dump of hacked Democratic documents in July 2016. He says he was present in Mr. Trump's office when Roger Stone, a Trump hanger-on, called to say he'd personally confirmed the dump with WikiLeaks founder Julian Assange. Mr. Cohen says Mr. Trump replied "to the effect of, 'wouldn't that be great.'"

Yet there is no evidence that Mr. Stone ever communicated with Mr. Assange, and Special Counsel Robert Mueller’s indictment makes no such claim. Mr. Cohen offered no evidence that Mr. Trump had a hand in hacking or releasing any emails, and it is hardly a surprise if Mr. Trump privately cheered the release of damaging information on Hillary Clinton. He said so publicly during the campaign.

Keep reading this editorial in The Wall Street Journal.