WASHINGTON — Senator Hagel yesterday became the latest Republican to call for the resignation of Attorney General Gonzales, saying disclosures about a sick bed visit to his predecessor have undermined his moral authority to lead the Justice Department.

Citing dramatic testimony a day earlier that showed that Mr. Gonzales, then the White House legal counsel, tried to undermine the department he now leads, Mr. Hagel demanded the attorney general’s resignation.

The American people deserve an attorney general, the chief law enforcement officer of our country, whose honesty and capability are beyond question,” Mr. Hagel, a Republican of Nebraska, said in a statement. “Attorney General Gonzales can no longer meet this standard. He has failed this country. He has lost the moral authority to lead.”

President Bush continued to stand by his longtime friend and adviser. Asked about Mr. Hagel’s comment on Mr. Gonzales’s moral authority, press secretary Tony Snow replied: “We disagree, and the president supports the attorney general.”

Mr. Hagel has hinted at seeking his party’s presidential nomination but has not officially declared his candidacy. Another Republican contender, Senator McCain of Arizona, last month called for Mr. Gonzales’s resignation.