President Trump’s defense in the impeachment trial began its second day of opening arguments on Monday — and counsel Ken Starr jumped straight into his main argument: Since Trump didn’t break the law, his actions don’t reach the threshold of an impeachable offense.

“The articles do not charge a crime or violation of established law,” said Starr. “I’m suggesting it’s a relevant factor. I think it’s a weighty factor.”

Starr’s analysis is counter to that of many legal experts. As Vox’s Ian Millhiser writes, a wide range of constitutional law scholars have concluded that a president does not need to commit a crime for a particular action to be considered worthy of impeachment.

But perhaps more importantly — or at least succinctly — there is ample evidence to suggest that Trump did break the law. In fact, the Government Accountability Office, a nonpartisan internal government watchdog, determined as much just two weeks ago.

On January 16, the GAO put out a strongly worded legal opinion regarding the Office of Management and Budget’s decision to delay military aid to Ukraine, and determined that this move was in violation of the Impoundment Control Act of 1974. As the ICA notes, a president can’t apply his own policy priorities to funds that have already been appropriated for a specific, different purpose by Congress.

Holding the Ukraine aid is something Trump has already confessed to — and doing so was a clear violation of the ICA, the GAO writes:

The President has narrow, limited authority to withhold appropriations under the Impoundment Control Act of 1974. OMB told GAO that it withheld the funds to ensure that they were not spent “in a manner that could conflict with the President’s foreign policy.” The law does not permit OMB to withhold funds for policy reasons.

Trump’s team has suggested the president withheld the aid because he was concerned about corruption and sharing costs with other nations — not coercing Kyiv into investigating the Biden family, as various witnesses testified during House Democrats’ impeachment inquiry last fall. However, either justification wouldn’t pass muster, according to the GAO.

As the Washington Post’s Aaron Blake writes, it’s worth pointing out that this opinion is not a criminal indictment — and the remedy for this violation, had Trump not released the aid eventually, would have taken the form of a lawsuit.

The White House has pushed back on the legal opinion’s conclusions, but House Democrats have signaled that it could serve as a key piece of evidence as the impeachment trial continues, Axios reports. Other points that Democrats have cited to counter this particular argument? The words of Republican Sen. Lindsey Graham and Trump counsel Alan Dershowitz.

“It certainly doesn’t have to be a crime if you have somebody who completely corrupts the office of president and who abuses trust and who poses great danger to our liberty, you don’t need a technical crime,” Dershowitz said in 1998, describing the types of actions that qualify as an impeachable offense.