WASHINGTON [Associate Press] — Joining a growing list of Republicans, former House Speaker Newt Gingrich said Sunday that Attorney General Alberto Gonzales should consider resigning. The possible presidential candidate said the botched firing of U.S. attorneys has destroyed Gonzales’ credibility as the nation’s top law enforcer.

“I think the country, in fact, would be much better served to have a new team at the Justice Department, across the board,” Gingrich said. “I cannot imagine how he is going to be effective for the rest of this administration. … They’re going to be involved in endless hearings.”

Sen. Charles Schumer, D-N.Y., who is helping lead the investigation into the firing of eight federal prosecutors, said Gingrich’s comments pointed to building bipartisan support for a new attorney general.

“This is another important voice who believes that the attorney general should step down for the good of the country and the good of the department,” Schumer said in a statement. “We hope both the attorney general and the president heed Speaker Gingrich’s message.”

Gonzales, a former White House counsel who became attorney general in 2005, is scheduled to testify April 17 before the Senate Judiciary Committee. It is a congressional showdown believed to be a make-or-break appearance for Gonzales.

The committee also has pledged to compel the testimony of White House officials such as Karl Rove and former counsel Harriet Miers to determine the extent of White House involvement. On Friday, Monica Goodling, the Justice Department’s liaison to the White House, abruptly quit after telling Congress she would not testify.

After the firings earlier this year, Gonzales initially asserted that the dismissals were performance-related, not based on political considerations, and that he was not directly involved in the decisions.

But testimony from his former chief of staff, Kyle Sampson, as well as e-mails between the department and the White House contradicted those claims, leading to a public apology from Gonzales.

On Sunday, Gingrich harshly criticized Gonzales’ judgment in allowing the firings to escalate into such a political scandal.

Gingrich noted that a president has every right to fire U.S. attorneys for any reason. Therefore, he said, all Gonzales had to do was to say that Bush wanted new people. Instead, Gingrich said, the attorney general made a series of misstatements from which he was forced later to backtrack.

“This is the most mishandled, artificial, self-created mess that I can remember in the years I’ve been active in public life,” Gingrich said. “The buck has to stop somewhere, and I’m assuming it’s the attorney general and his immediate team.”

In recent weeks, several Republicans have joined Democrats in saying Gonzales should consider resigning, including Sens. John Sununu of New Hampshire and Gordon Smith of Oregon and Reps. Dana Rohrabacher of California, Tom Tancredo of Colorado and Lee Terry of Nebraska.

Other Republicans, including administration allies Jon Kyl of Arizona and John Cornyn of Texas, have acknowledged that Gonzales badly mishandled the matter and needed to explain himself quickly.

“I think the confusion and the ham-handed way that these firings was done certainly undermines the confidence of the Justice Department,” Kyl said Sunday. “And part of his effort to come up and testify before the Hill will be to restore some of that confidence.”

Schumer said the controversy is the latest evidence of a leadership failure at the department.

“The gravity of this situation is shown by the fact that several Republicans have called for the attorney general to resign,” he said. “The fact that the attorney general is the president’s friend and was the president’s counsel for years does not alone make him qualified to be attorney general.”

Gingrich and Schumer appeared on “Fox News Sunday,” and Kyl spoke on ABC’s “This Week.”