WASHINGTON (CNN) -- Sen. Chuck Hagel, R-Nebraska, called on Attorney General Alberto Gonzales to resign Tuesday, a day after former Deputy Attorney General James Comey testified before the Senate Judiciary Committee that Gonzales, then White House counsel, tried to coerce a hospitalized Attorney General John Ashcroft in 2004 to reauthorize the National Security Agency's domestic surveillance program.

"[Gonzales] has failed this country," Hagel said. "He has lost the moral authority to lead. Comey's testimony yesterday brings to light the latest episode in a series of questionable actions by Attorney General Gonzales. It is another part of a pattern of flawed decision making by the attorney general."

Hagel, an increasingly loud critic of the Bush administration, has said he might mount a White House bid later this year.