In fairness to House Speaker Nancy Pelosi, the events that moved her to support impeachment after months of dismissing the left wing of her caucus are exactly what the Framers had in mind when they crafted the impeachment clause, which was to prevent a corrupt chief executive from using his official powers to keep himself in office. That precisely describes Trump’s use of his official powers to strong-arm a foreign government into implicating his political rivals. The Framers forced the chief executive to face election every four years in order to prevent the president from becoming a king, but they recognized that a corrupt president might use his powers to keep himself in office in perpetuity, and that impeachment was needed as a last resort. Yet Trump is only the most vulgar expression of the anti-democratic streak spreading in the Republican Party, and the forces that propelled his candidacy are the same ones that may shield him from accountability.

In July, President Trump ordered his chief of staff, Mick Mulvaney, to withhold $400 million in aid that Congress had designated for Ukraine. Last month, the inspector general of the intelligence community told the chair and ranking member of the House Intelligence Committee, Democrat Adam Schiff and Republican Devin Nunes, that someone had filed an “urgent” and “credible” whistle-blower complaint. The day after Schiff formally requested the complaint, the Trump administration released the hundreds of millions of dollars it had been withholding.

Media outlets, which had been reporting on efforts by Trump’s personal attorney Rudy Giuliani to dig up dirt on former Vice President Joe Biden’s son Hunter Biden, who was on the board of the Ukrainian energy company Burisma, revealed that the complaint was related to that effort. Days after withholding aid to Ukraine, according to a White House summary of the call between Trump and Ukrainian President Volodymyr Zelensky, Trump demanded that Ukraine investigate the Bidens. Zelensky brought up an impending sale of American Javelin missiles to Ukraine, to which Trump replied, “I would like you to do us a favor, though.”

Apparently under the belief that Ukraine is somehow in possession of the Democratic National Committee’s servers that were hacked in a Russian effort to swing the 2016 election in Trump’s favor, Trump asked Zelensky to “get to the bottom of it,” because of his belief that the Russia investigation “started with Ukraine.” Trump then repeatedly pressed Zelensky to investigate the Bidens, and to speak to Giuliani and Attorney General William Barr about them, suggesting that if Ukraine would not prosecute Trump’s political rivals, it provide the U.S. Justice Department with a pretext for doing so.

Trump himself helpfully summarized the point of the call a few days ago, although he insisted that he had not tied aid to going after the Bidens. “The conversation I had was largely congratulatory. It was largely corruption—all of the corruption taking place. It was largely the fact that we don’t want our people, like Vice President Biden and his son, creating to [sic] the corruption already in the Ukraine.” As Trump’s former attorney Michael Cohen testified before Congress, like any organized-crime boss, the president understands how to communicate his demands implicitly. Even so, the summary of the call makes clear Trump’s message that if Zelensky wants the promised military aid, he must accede to Trump’s requests.