ANNAPOLIS, Md. -- Ron Wyden figured he wouldn't get a chance to ask President Obama directly. So, in an interview Wednesday at the Democrats' Senate Retreat, the member of the Intelligence Committee -- a day before the president's nominee to be CIA director -- said he had serious questions about the non-classified Justice Department memo, obtained by NBC News.

"The memo doesn't answer the central questions," said the Oregon senator and longtime critic of the drone strikes. To Wyden, the central questions revolve around, "When does the government have the legal right to kill an American?"

The memo outlines the administration's justification for the targeted killing of American citizens overseas -- via drone strikes -- if they are considered high-level al Qaeda operatives and may be plotting attacks against the U.S.

The retreat in Annapolis was highlighted by a visit from the president. He had received a letter from Wyden and 10 other senators, both Republicans and Democrats, asking to see the rationale for that "right," as outlined in the memo.

In fact, Wyden contended, "The administration has essentially been stonewalling the committee and myself and others for over two years by not actually making that memo available with someone willing to answer questions about it."

Brennan's confirmation hearing Thursday will give Wyden his chance.

"And I want it understood that because this is such a central time, where you have an individual with such enormous influence who's really the architect of the counter-terror policy in the Obama administration," Wyden said, "that I'm going to pull out all the stops to get the actual legal analysis, because without it, in effect, the administration is, in effect, practicing secret law."

Brennan has been the president's top anti-terrorism adviser and has 25 years of CIA experience.

Wyden says the inability to get answers, coupled with the thought that life-and-death targeted killing decisions can be made without any judicial process "makes a mockery out of the oversight process."

Before hustling in to hear the president, Wyden concluded, "In effect, this position is no different than the position the Bush administration adhered to in [the overall war on terror], which, I guess is largely, 'Trust us. Trust us; we'll make the right judgments.'"

At the White House, facing a second day of questions about the matter, spokesman Jay Carney indicated the president himself is not worried by the leak.

"He thinks that it is legitimate to ask questions about how we prosecute the war against al Qaeda," Carney said.