WASHINGTON (AP) - North Dakota's two senators, Democrats Kent Conrad and Byron Dorgan, say Attorney General Alberto Gonzales should step down.

"A line has been crossed," Conrad said Monday. "He needs to go, and the sooner the better."

Two of their Democratic colleagues, Chuck Schumer of New York and Dianne Feinstein of California, have said they will seek a nonbinding Senate no-confidence vote, saying the Republican attorney general is too weakened to run the Justice Department. The department is embroiled in probes of the firings of eight federal prosecutors and allegations that it has become too politicized.

"There is no question in my mind that he has conducted his office in a partisan way and that's very damaging to the administration of justice in this country," Conrad said. "That just can't be permitted."

Dorgan criticized Gonzales' recent testimony on Capitol Hill, in which he often claimed a hazy memory about his role in the prosecutor firings.

"He has either not told the truth, or he is incompetent," Dorgan said. "Either he doesn't know what went on or he's deliberately been untruthful. Either of those is cause for his resignation."

Dorgan predicted that Gonzales' opponents would win a vote of no confidence.

"My guess is that it would likely achieve a majority in the Senate," he said.

Conrad and Dorgan join a bipartisan chorus of senators calling for Gonzales to step down. On Sunday, the top Republican on the Senate Judiciary Committee predicted Gonzales would do that before the Senate vote.

President Bush on Monday called that vote "pure political theater" and stood by his embattled friend.