Presidential candidate Barack Obama accused former President Bill Clinton of distorting his words as the Democratic race in South Carolina heated up on Monday.

Meanwhile, Republican presidential hopefuls kept their focus on economics as they began campaigning for the Jan. 29 primary in Florida.

Obama, who was edged out by the ex-president's wife Hillary Rodham Clinton in the Saturday caucuses in Nevada, had harsh words for Bill Clinton, who is beloved in many Democratic circles _ including among many blacks, who could be key to a win in South Carolina's weekend primary.

The former president "has taken his advocacy on behalf of his wife to a level that I think is pretty troubling" by making statement that are not supported by facts, Obama said in an interview broadcast Monday on ABC's "Good Morning America."

The Clinton campaign has suggested it would continue pointing out inconsistencies in Obama's record.

Republicans are preparing for delegate-rich Florida, where the race remains wide open despite John McCain's recent wins in South Carolina and New Hampshire. A win in Florida would afford the candidate a whopping 57 delegates and a huge jolt of energy in the run-up to Feb. 5, when 22 states hold nominating contests.

Clinton and Obama have been locked in a fierce battle for the party's nomination in a history-making campaign that pits a black man and a woman. Obama won the Jan. 3 Iowa caucuses and Clinton emerged triumphant in New Hampshire, five days later.

Their campaign has vacillated between congenial exchanges, a dispute on race and, before Nevada's contest Saturday, charges of dirty politics. So far, no clear front-runner has emerged, making the Jan. 26 contest in South Carolina, where blacks make up about 50 percent of the Democratic electorate, particularly important going into the Feb. 5 de facto national primary.

Trailing candidate John Edwards is looking to make the Democratic contest a three-way race with a strong showing in South Carolina, which neighbors his home state of North Carolina.

Edwards got 4 percent of support in Nevada, compared with Clinton's 51 percent and Obama's 45 percent.

On Sunday, Obama took to the pulpit at Martin Luther King Jr.'s Ebenezer Baptist Church in Atlanta on the eve of the federal holiday marking the civil rights hero's birth 79 years ago. He based his speech on King's quote that "Unity is the great need of the hour."

Obama is counting on blacks to stick with him in South Carolina to halt his losing streak in the last two state races, and his campaign has worked to overcome concerns among black voters that he would not be able to win an election in white America. He lost Nevada despite winning 83 percent of blacks, who made up 15 percent of the total vote.