African Americans candidates for the highest political offices - governor, senator and president - historically win the lion's share of the black vote. But they rarely attract enough white votes to win elections. And that is what makes Obama's campaign so different and so successful that it has overwhelming black support, yes, but enough white voters to win one primary after another, which is raising possibilities that were only pipe dreams a few years ago.
Obama's a great speaker. But so was the Reverend Jesse Jackson when he ran for president in '84 and '88. And so was the Reverend Al Sharpton, who ran four years ago.
But Obama is the first viable African American candidate, a Democrat with good chance of winning his party's nomination this year, and perhaps the presidency itself. Jesse Jackson's wife, Jackie, who is backing Hillary Clinton this year, has some thoughts about why Obama's been so successful.
"The country has changed. The country has changed to the better because they are more accepting of an African American candidate, which is wonderful," she said.
Obama's also a U.S. senator with a Harvard law degree and a campaign staff that's recruiting thousands of volunteers, raising tens of millions of dollars and organizing sophisticated political and Internet operations in dozens of states, all of which is light years ahead of the previous black candidates. And according to Dan Smith, who's been watching politics in Washington D.C. for decades, something else is going on this year.
"Two things - I think the American people, especially the young people, like change. My other personal reason is that there is a lot of white guilt out there, people who want to make up for? the way blacks were treated years ago," he said.
But Smith says as much as attitudes may have changed, and as much as Obama and his campaign have exceeded expectations, the real test will come if he wins the nomination.
"This country is really not ready, in my judgment, to totally support a black candidate," said Smith.
That was probably truer at the beginning of the Obama campaign when he was only attracting a small percentage of white voters. But as other candidates dropped out and Obama got better known, the trend began to change. So by the time the Potomac primaries went down on Tuesday, he actually got more white votes than Clinton. And the polling indicates that with the widespread support of political independents, he matched up better than Clinton against Republican John McCain.