In this photo provided by CBS News, U.N. Ambassador Susan Rice comments on the attack in Benghazi as she appears on CBS's “Face The Nation” on Sept.16. (Handout/GETTY IMAGES)

The House of Representatives usually plays little formal role in foreign affairs, but a sizable group of House Republicans has launched a campaign against a high-ranking State Department official over the Sept. 11 attack in Libya.

The fresh GOP criticism of U.N. Ambassador Susan Rice has angered many Democrats, who say Republicans are making her a scapegoat for the administration’s response to the deadly assault on the U.S. diplomatic mission in Benghazi.

House Democrat James E. Clyburn (S.C.) — the highest-ranking black lawmaker in Congress — has also questioned whether Republicans are singling out Rice, a potential nominee for secretary of state, because she is black.

Building on doubts first raised by senior GOP senators, 97 House Republicans co-signed a letter this week warning President Obama that Rice’s public comments after the attack on the mission in Benghazi “caused irreparable damage to her credibility both at home and around the world.”

The members also told Obama that making Rice “the face of U.S. foreign policy” in the coming years as his next secretary of state “would greatly undermine your desire to improve U.S. relations with the world and continue to build trust with the American people.”

“Ambassador Rice is widely viewed as having either willfully or incompetently misled the American public in the Benghazi matter,” the lawmakers wrote. “Her actions plausibly give U.S. allies (and rivals) abroad reason to question U.S. commitment and credibility when needed.”

Obama has not signaled whether he plans to nominate Rice to succeed Hillary Rodham Clinton, who plans to step down in the coming weeks. But he provided a spirited defense of Rice last week after Sens. John McCain (R-Ariz.) and Lindsey O. Graham (R-S.C.) voiced sharp criticism of her actions in the response to Libya.

Rice, 47, served as an adviser to Obama’s 2008 presidential campaign and was later tapped to serve as U.S. envoy to the United Nations.

The focus of the GOP criticism is a series of television appearances by Rice after the attack, which she characterized as growing out of a spontaneous demonstration against an anti-Muslim video. But reports from the ground and statements by administration officials since have varied from her initial statements.

The Monday letter was written by Rep. Jeff Duncan (R-S.C.), chairman of a House subcommittee on terrorism. Those that signed the letter are among the most conservative House Republicans, and at least 10 of them lost reelection bids this month.

Although only the Senate will have a say on Obama’s eventual nominee, veteran congressional aides noted that many of the House Republicans who signed the letter are closely aligned on most issues with several GOP members of the Senate Foreign Relations Committee, including Jim DeMint (S.C.), James M. Inhofe (Okla.), Mike Lee (Utah) and Marco Rubio (Fla.).

Congressional Democrats have joined Obama in accusing Republicans of unfairly attempting to scapegoat Rice. Black Democrats are especially upset that Republicans continue to use the word “incompetent” to describe Rice, a Rhodes scholar and veteran of the Bill Clinton administration.

Clyburn, the third-ranking House Democrat, said Tuesday that use of the term amounts to using racial “code words.”

“We in the South know what that means,” he said in an interview. “I take offense when people use those words. I have a problem with them.”

“They are going to disagree with Rice’s politics, but if they do, just say she's wrong,” Clyburn added. “When you apply the word ‘incompetent,’ that personalizes this thing, it goes beyond politics, because it’s about who and what she is — it’s character assassination.”

The remarks echo comments last week by Rep. Marcia L. Fudge (D-Ohio), the new chairman of the Congressional Black Caucus, who suggested Rice was being targeted for her race and sex.

Duncan was traveling overseas Tuesday and unavailable for comment. His spokesman, Allen Klump, called Clyburn’s comments “baseless, false and disappointing.”

House Republicans have also been sharply critical of another senior black administration official, Attorney General Eric H. Holder Jr., for his handling of the “Fast and Furious” gun-tracking scandal. The probe ultimately led the GOP-controlled House to hold Holder in contempt of Congress.

But GOP aides said Tuesday that the new focus on the Libya attack is born out of genuine concern over a legitimate national security blunder: “The election’s over, we’re not talking about elections, we’re talking about the conduct of the administration,” said one aide who was unauthorized to speak publicly on the matter. “And there is genuine concern with how the administration handled this.”

A national survey published Monday by the Pew Research Center for the People and the Press showed that Republicans are particularly interested in the fallout from the Benghazi attacks. About 28 percent of respondents said they are closely monitoring the issue, according to the Pew Research Center for the People and the Press. The survey found that Republicans (42 percent) are much more likely than Democrats (21 percent) or independents (22 percent) to be closely tracking the affair.