WASHINGTON The trenchant debate over a UN-sponsored conference on racism became even more volatile Tuesday, as divided members of the U.S. Congress took turns praising and lambasting the White House for its announced possible boycott of the event.

The United States on Friday threatened to stay away from the conference if the agenda includes talk of reparations for slavery and colonialism or a measure equating Zionism with racism.

But some members of Congress -- including those in the congressional black caucus at a hearing on Tuesday -- slammed the White House, saying that the United States would be forfeiting an important opportunity to tackle long-simmering domestic issues of racial strife by staying away.

"Given that 30 percent of the U.S. population consists of people of color and that we have all experienced racism firsthand, I have to wonder if the Bush administration's position ... is just politically dumb or if it is perhaps indicative of something more malignant," AFP quoted Cynthia McKinney, a Democratic member of Congress from Georgia and ranking member of the House subcommittee on international operations and human rights as saying.

McKinney, an African-American, accused the White House of adopting "an intransigent, if not openly hostile, view of the entire conference."

"I am compelled to ask the obvious question, then, that no one will ask: is the Bush White House just full of latent racists?" McKinney said.

"For U.S. not to participate in the conference would be a disaster," said Congressman Donald Payne, a Democrat from New Jersey.

"It is totally wrong," echoed California Democrat Barbara Lee, who is also black. "The U.S. unwillingness to address the issue sends the wrong message."

"As a country, we have not yet conquered the twin problems of racism and economic inequality," Lee added.

Attendance by the United States at the conference, she said, would represent "a giant step toward racial healing."

But there was also praise for the stance taken by President George W. Bush's administration.

California Congressman Tom Lantos applauded the White House, saying that it was important for the United States to stand four-square with its close ally Israel.

Lantos, the only Holocaust survivor in the U.S. Congress, complained that a "group of nations and a group of organizations have hijacked" the agenda by forwarding the Zionism proposal.

Ben Gilman, a republican from New York also advocated that Washington snub the UN conference, warning that the anti-Zionism clause of the declaration was dangerously inflammatory.

"Violence can result" if it is adopted as it stands, he warned. "The language in that declaration must be resisted."

Washington skipped two previous UN conferences on racism, in 1978 and 1983, because of a similar Zionism provision. Britain, France and Germany have also objected to slavery being addressed at this year's conference.

Lantos said that Washington should send "a low-level delegation or no delegation at all" to the conference, which is to be held in Durban on South Africa's east coast from August 31 to September 7.

On Monday, UN High Commissioner for Human Rights Mary Robinson urged Arab countries to back away from demands to equate Zionism with racism, saying that "to do so is putting the Durban conference at risk."

Lantos, who spoke recently by telephone with the commissioner, said Robinson sounded optimistic that the rift over slavery and Zionism might not, in the end, derail the entire conference.

But he said he feared that opponents of Israel would take a back-door channel.

"The attack will take a somewhat different form. It will focus on settlements" rather than directly on Zionism, he said.

Meanwhile, negotiations in Geneva on a draft declaration and program of action to be adopted at the end of the conference were still underway and are set to run until August 10.

Delegations from 194 countries are expected to attend the conference, including dozens of heads of state and 160 foreign ministers.