President Donald Trump had gotten off scot-free. ”A great day for me,” he declared on July 24. Former special counsel Robert Mueller’s testimony about Trump’s alleged obstruction of the investigation into Russian interference in the 2016 election had failed to convince House Speaker Nancy Pelosi ― let alone congressional Republicans ― to impeach him.

With not one member of his circle in prison for attempting to collude with a foreign power, and with the prospect of impeachment rapidly fading thanks to Pelosi’s hand-wringing and stonewalling, Trump did what any rational leader would do: He apparently did it again.

The day after Mueller’s testimony, Trump called Ukrainian President Volodymyr Zelensky and pressured Zelensky to help him win the 2020 election by investigating former Vice President Joe Biden’s son, Hunter, The Wall Street Journal reported Friday. In the weeks that followed, Trump refused to grant Zelensky a meeting at the White House and halted $250 million of congressionally authorized military aid to the country, raising the possibility that the president was, as The Washington Post put it in an unsigned editorial, “not just soliciting Ukraine’s help with his presidential campaign” but using U.S. military aid to “extort it.”

“That allegation, if true, would unambiguously constitute an impeachable offense,” national security expert Benjamin Wittes wrote Friday. “That would be a very big deal indeed.”

If the reports are correct, “there is truly no bottom to President Trump’s willingness to abuse his power and abase our country,” Joe Biden said in a statement released late Friday. “This behavior is particularly abhorrent because it exploits the foreign policy of our country and undermines our national security for political purposes. It means that he used the power and resources of the United States to pressure a sovereign nation… to subvert the rule of law in the express hope of extracting a political favor.”

For months, Trump’s personal lawyer Rudy Giuliani has been pushing the unfounded theory that Joe Biden, when he was vice president, pressured Ukraine to fire the country’s former special prosecutor because Biden was mad the prosecutor was investigating a gas company with ties to his son Hunter. Giuliani’s theory is based on a web of misinformation. There’s no evidence that Joe Biden knew anything about an investigation into Hunter Biden. And the U.S. government, along with the European Union and the International Monetary Fund, wanted Ukraine to fire the prosecutor. That didn’t have anything to do with Hunter Biden. Instead, the U.S. and its allies wanted the prosecutor gone because he wasn’t doing enough to investigate corruption in Ukraine.

Those facts didn’t stop Trump from pushing for a probe: During a July 25 phone call with Zelensky, Trump urged his Ukrainian counterpart about eight times to help Giuliani investigate the Bidens, according to the Journal. The details of that phone call — first reported Friday by The Wall Street Journal, then confirmed by The Washington Post and The New York Times — are the subject of a still-secret whistleblower complaint the president and his allies are fighting hard to keep out of the hands of lawmakers.

Trump made his pitch on July 25, just after Mueller’s underwhelming testimony on Capitol Hill. Mueller’s 22-month investigation into whether the Trump campaign colluded with Moscow to tilt the election in Trump’s favor was over. Despite compiling hundreds of pages detailing the campaign’s outreach to Russian officials — and Trump’s subsequent efforts to cover it up — Mueller did not recommend criminal charges against the president and instead deferred to Congress. But congressional leadership balked at conducting oversight and indefinitely stalled launching an impeachment proceeding.