Just before they left Philadelphia, the Constitution’s framers tackled a question that special counsel Robert S. Mueller III’s report has revived, 232 years later: Could the president abuse his pardon power to obstruct justice?

On September 15, 1787 — with the Constitution drafted, the summer’s heat cooling and the convention delegates at the Pennsylvania State House eager to go home — Virginia Gov. Edmund Randolph stood to voice a last-minute concern. The president, Randolph said, shouldn’t be able to pardon treason.

“The President may himself be guilty,” Randolph argued. “The Traytors may be his own instruments.”

Mueller’s report, which mentions presidential pardons 64 times, closely scrutinizes President Trump’s comments about the possibility of pardoning former aides Paul Manafort, Michael Cohen and Michael Flynn.

“Evidence concerning the President’s conduct towards Manafort indicates that the President intended to encourage Manafort to not cooperate with the government,” the report states. “The evidence supports the inference that the President intended Manafort to believe that he could receive a pardon,” Mueller adds, “which would make cooperation with the government as a means of obtaining a lesser sentence unnecessary.”

The Constitution doesn’t allow the president to abuse his pardon power, Mueller’s report says. “Congress has the authority to prohibit the corrupt use of anything of value to influence the testimony of another person,” Mueller wrote, “which would include the offer or promise of a pardon to induce a person to testify falsely or not to testify at all.”

When the Founding Fathers debated the Constitution, they contemplated the very concern Mueller examined: whether a president might abuse his pardon power to obstruct justice or protect himself from investigation. The Founders had a ready answer to that scenario: a president who uses his pardon power corruptly can be impeached.

The Constitution’s framers were used to the idea of official pardons for crimes. Some state governors had pardon powers, modeled after the king of England’s authority to grant mercy. So giving the president the same power to pardon federal crimes wasn’t controversial at the Constitutional Convention, until the very end.

Charles Pinckney of South Carolina included pardons in his proposed list of presidential powers on the convention’s fourth day, May 29, 1787, and no one debated it for months. Without “the benign prerogative of pardoning,” Alexander Hamilton wrote later in the Federalist Papers, “justice would wear a countenance too sanguinary and cruel.”

Randolph finally questioned the president’s broad pardon power on the convention’s next-to-last day, Sept. 15. An early supporter of writing a new Constitution, the 36-year-old Virginia governor had since joined a small group of dissenters who feared the proposed federal government’s broad powers.

So Randolph proposed an amendment to the president’s authority to “grant Reprieves and Pardons for Offences against the United States, except in Cases of Impeachments.” He moved to add, “except cases of treason.” Randolph feared a criminal president might pardon his co-conspirators. “The prerogative of pardon in these cases was too great a trust,” he argued.

But James Wilson of Pennsylvania, one of the convention’s sharpest legal minds, argued that the draft Constitution already included a method for stopping a rogue president. “Pardon is necessary for cases of treason, and is best placed in the hands of the Executive,” Wilson argued. “If he be himself a party to the guilt he can be impeached and prosecuted.” The convention rejected Randolph’s amendment by a vote of eight states to two.

Yet the debate about presidential pardons didn’t end there. George Mason, another dissenting delegate from Virginia, had seconded Randolph’s motion. The main author of the Virginia Declaration of Rights, Mason refused to sign the Constitution, declaring that “it would end either in monarchy, or a tyrannical aristocracy.”

After the convention, Mason took his concerns public and became an Anti-Federalist, an opponent of ratification. His Anti-Federalist paper, Objections to the Proposed Federal Constitution, written in October 1787, included his concerns about the pardon power.

“The President of the United States has the unrestrained power of granting pardon for treason,” Mason wrote, “which may be sometimes exercised to screen from punishment those whom he had secretly instigated to commit the crime, and thereby prevent a discovery of his own guilt.”

Hamilton was probably responding to Mason when he defended the president’s pardon power in Federalist No. 74. “The supposition of the connivance of the Chief Magistrate ought not to be entirely excluded,” Hamilton conceded. But another scenario outweighed that danger, Hamilton argued: Giving the president the power to pardon rebels might help end a civil war.

“In seasons of insurrection or rebellion, there are often critical moments, when a well-timed offer of pardon to the insurgents or rebels may restore the tranquillity of the commonwealth,” Hamilton wrote. Waiting for Congress to convene and act “could let slip the golden opportunity.”

Undaunted, Mason brought his objections to the Virginia ratifying convention. It met in Richmond’s New Academy theater in June 1788, a crucial time. Eight of the required nine states had ratified the Constitution, but the debate in populous Virginia and New York was too close to call.

So the four-week Virginia convention became one of the great constitutional debates of all time. Spectators crowded the theater to hear future president James Madison, 37, argue for the Constitution, while an older generation of patriots, Mason, 62, and the fiery Patrick Henry, 52, argued against it. Mason insisted on debating the Constitution clause by clause. Madison accepted the challenge. Freewheeling arguments took up two weeks, including a nearly day-long speech in which Henry warned of “the probability of the President’s enslaving America.”

When Mason brought up the pardon power this time, he didn’t only imagine a case of treason. He warned that a president could abuse pardons to obstruct investigations of any crimes involving him and his confidants.

“The president ought not to have the power of pardoning, because he may frequently pardon crimes which were advised by himself,” Mason warned. “If he has the power of granting pardons before indictment, or conviction, may he not stop inquiry and prevent detection? The case of treason ought, at least, to be excepted.”

Madison had a ready answer. “There is one security in this case,” he said. “If the President be connected, in any suspicious manner, with any person, and there be grounds to believe he will shelter him, the House of Representatives can impeach him.”

Weeks later, the Constitution became law. The Virginia delegates ratified the Constitution on June 25, 1788, by a vote of 89-79. New Hampshire ratified it on June 21, New York on June 26. Presidents, from Washington to Trump, would have sole discretion to issue pardons for federal crimes — but not the freedom to corrupt the pardon power.

Erick Trickey is a Boston-based freelance writer who teaches magazine journalism at Boston University.

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