By Edward Epstein, CQ Staff

Many senior black Democrats, veterans of the civil rights struggles of the past several decades, can’t quite believe that Barack Obama , the son of a black Kenyan immigrant and a white mother from Kansas, is now their party’s nominee for president. It all seems too unreal to them.

“No, I never thought I would live to see it,” said 68-year-old James E. Clyburn of South Carolina, who as House majority whip is the highest-ranking African-American in Congress. “I thought it would happen one day, but I never thought I would live to see it. It will be a great thing to have lived to see it.”

“There is a sense of awe and pride,’’ said Rep. Sheila Jackson Lee of Texas, a former civil rights worker for the Southern Christian Leadership Conference. “I don’t know if we’ll be able to contain ourselves when he speaks Thursday night,’’ added Jackson Lee, 58.

She said her 82-year-old mother if floating on air: “She is besides herself. She is a daughter of the South who never had the opportunities that her own daughter had.”

Rep. Charles B. Rangel of New York, 78, who was an early supporter of Hillary Rodham Clinton ’s presidential bid, said that early on in the campaign for the 2008 nomination he didn’t think Obama could win. “As a matter of fact, it wasn’t until Iowa that it became a reality to me,” Rangel said. In January’s Iowa caucuses that kicked off the nominating campaign, Obama came in first, with John Edwards second and Clinton third.

Willie L. Brown Jr., the former mayor of San Francisco and California Assembly speaker, said, “As an African-American I am immensely proud.”

But Brown cautioned that Obama’s race — the country is about 12 percent black — could still hurt him in the fall campaign against Republican John McCain .

“I’m still skeptical he’ll become president because this is America and race is still a major component,” added Brown, who learned from bitter experience that even when polls show a black candidate leading, the result can be different on Election Day.

In the 1982 California governor’s race — in what has become known as the “Bradley Effect” — Tom Bradley, the black mayor of Los Angeles, went into the election with a polling lead, only to lose narrowly to Republican George Deukmejian. The reason for Bradley’s defeat, analysts have said ever since, is that some white voters will tell pollsters they plan to vote for a black candidate but don’t really intend to once they get inside the voting booth.

Brown said that the best way for an African-American candidate to win statewide or nationally is to over-achieve. “Obama has to make it clear that quality ought to be the basis on which people are elected and that color is secondary,” Brown said.

One cushion for Obama against such racial doubts is for the Democratic Party to register every black voter it can, since the Illinois senator is expected to benefit from a heavy and enthusiastic African-American vote. Jackson Lee estimated that in Harris County, which includes her hometown of Houston, there are still some unregistered eligible minority voters. She said the Obama campaign is working with other groups on a massive registration drive for the fall.

But Rev. Amos Brown, a delegate from San Francisco, said that in California black voter registration efforts are lagging. “It’s one thing to be excited and to celebrate, and another thing to be engaged and make the big effort,” he said.

Brown said that, in some states, a big effort in the minority community is needed to offset a return of the Bradley Effect. “You have to offset the negative, traditional voters,” he said.