President Obama’s white paper justification for carrying out drone strikes against U.S. citizens suspected of terrorism could “swallow the rule” guaranteeing the due process rights of Americans, Sen. Mike Lee, R-Utah, suggested today.

“There is nothing more serious than the taking of the life of a U.S. citizen by the U.S. government,” Lee said in a phone interview with The Washington Examiner while discussing the Justice Department white paper that explains some of the rationale behind the drone strike counter-terrorism program.

“You would think that consistent with the principles of due process, the government shouldn’t be able to kill one of its own citizens without some kind of showing that they present an imminent threat,” he continued. “But when you dig a little bit deeper into this white paper . . . they have sort of a loose [definition] of ‘imminent’.”

NBC News reported that it had obtained an unclassified DOJ white paper that articulated a broader claim of power to kill U.S. citizens suspected of terrorist activities.

“The condition that an operational  leader present an ‘imminent’ threat of violent attack against the United States does not require the United States to have clear evidence that a specific attack on U.S. persons and interests will take place in the immediate future,” NBC quotes the memo as saying.

“That has the potential to swallow the rule,” Lee warned. “If you’re going to regard somebody as presenting an imminent threat of an attack on the U.S. simply because you have concluded that they are an ‘operational leader’ or they are involved in planning an attack in one way or another, you find yourself giving way to much discretion to the government.”

Lee said the president needs to be more transparent with Congress about the drone strike program as pertaining to American citizens.

“I certainly think that Members of Congress ought to have the ability to review their legal analysis, regardless of what they make public,” he said. “They have not made that available, at least not to me, and as a member of the Judiciary Committee I think I ought to have access to it.”

The Senate Judiciary Committee has oversight jurisdiction of the Justice Department, but the White House has only given Senate Intelligence Committee members access to a memo from the Office of Legal Counsel that provides a more detailed legal justification for the program. The lawmakers are not allowed to make copies, take notes, or reveal the memo to their staff.

“We know that in some instances where the government has released its legal analysis, it gets it wrong,” Lee recalled, citing the D.C. Circuit Court of Appeals just repudiated the Obama Justice Department’s legal analysis for making ‘recess’ appointments when Congress is in session.

The former appellate lawyer also criticized the White House for failing to identify a constitutional principle that would prevent the U.S. military from carrying out a drone strike on a suspected American terrorist in the United States.

“They ought to be able to articulate that,” Lee told The Examiner. “To whatever extent they make a difference between their operations here and their operations elsewhere, they ought to have some explanation for that, and the mere fact that they don’t have one is itself cause for concern.”

“I am not a lawyer and these are the kinds of things that are probably best expressed and explained by lawyers,” White House Press Secretary Jay Carney told reporters when asked why the administration’s argument for killing Americans overseas doesn’t also allow Obama to order strikes within the country. “There are issues here about . . . feasibility of capture that I think are pertinent to that question.”