As he works on proposals to increase oversight of drone strikes on U.S. citizens, Sen. Angus King has been reading the Federalist Papers.

Mr. King, a Maine independent who caucuses with the Democrats, has emerged as a leading proponent of creating some sort of oversight mechanism to review presidential decisions to target U.S. citizens in counter-terrorism strikes.

To guide his decision making, Mr. King has been reading the writings of James Madison.

“The framers were very smart guys,” Mr. King said. “Their knowledge of human nature is extraordinarily. They were trying to write a document reflective of their understanding of human natures.”

Mr. King said he has been particularly focused on the fourth president’s writing about how war affects society, and looking for writings that might be applicable to the debate over counter-terrorism strikes.

“They were very conscious of an executive who could over reach when it came to his own citizens,“ Mr. King said.

Working with the Senate Intelligence Committee staff, Mr. King has been trying to develop a proposal that would provide something of a check on presidential power to target U.S. citizens.  Mr. King said the proposal could take the form of a judicial review, a “drone court.” It could also be an independent review within the executive branch, something more akin to an inspector general.

Whatever the check, Mr. King rebuffed criticism that such a review would intrude on split-second battlefield decisions.

“Targeting these people takes months,” Mr. King said. “It is not an exigent situation. Maybe there is an opportunity here for a check that doesn’t impede the commander-in-chief responsibility.”

In a speech Monday, former Defense Department General Counsel Jeh Johnson suggested many proposals for drone courts would be unconstitutional, intruding on the President’s commander-in-chief authority.

But Mr. King said that constitutional provision must be balanced against the due process rights laid out in the Fifth Amendment.

“There is a path to be trod here,” Mr. King said, “between the two provisions that honors the fundamental principle the framers were trying to get at while not compromising the president’s paramount authority to defend the country.”