I am a Republican and former federal prosecutor who voted for Donald Trump in 2016. But I was deeply dismayed by the way his lawyers defended his misbegotten dealings with Ukraine during the Senate impeachment trial. Unlike Mr. Trump’s supporters, I believe the president might well be guilty of breaking the law.

Even without the additional witnesses and documents that the Senate Republicans refused to subpoena, the evidence available to date has established a prima facie case of bribery, a felony under federal law, against Mr. Trump. The articles of impeachment do not use the word bribery, but the House Judiciary Committee did in a report, and for good reason: The proof is there, for the following reasons.

If the president corruptly demanded or sought anything of value to influence an official act, then he would be guilty of bribery. “In other words, for bribery there must be a quid pro quo — a specific intent to give or receive something of value in exchange for an official act,” the Supreme Court held in United States v. Sun-Diamond Growers of California in 1999.

Federal courts around the country have interpreted “anything of value” to include intangible things — in this case, the announcement by Ukraine of an investigation into former Vice President Joe Biden and his son Hunter. The official action in question to be offered in exchange was the release of American military assistance to Ukraine, a country at war with Russia. That military assistance was unlawfully withheld in contravention of the president’s constitutional obligation to “faithfully execute” the law as Congress enacts it, the United States Government Accountability Office found.