As the presidential campaign lurches deeper into the netherworld of attack politics, the Democratic Party is becoming dangerously polarized. Hillary Clinton's and Barack Obama's supporters increasingly say they wouldn't be happy with the opposing candidate as their nominee, and the two rivals feel free to bash each other more than ever.

Obama got back on the winning track by capturing the Wyoming caucuses March 8 and then the Mississippi primary March 11. He holds a lead of about 130 delegates. The next big test is scheduled for April 22 in Pennsylvania, where 158 delegates will be awarded and Clinton leads solidly in the polls. The next several weeks will give the candidates a lengthy period to raise money, refine their messages, and zero in on each other. They are losing no time on all fronts.

The latest dust-up focused on former Rep. Geraldine Ferraro of New York, a supporter of Clinton, member of her finance committee, and the Democratic vice presidential nominee in 1984. She told the Daily Breeze of Torrance, Calif.: "If Obama was a white man, he would not be in this position. And if he was a woman (of any color), he would not be in this position. He happens to be very lucky to be who he is." After Obama called her remarks absurd, Ferraro added fuel to the fire. "I really think they're attacking me because I'm white," she said, contending later that her remarks were being unfairly "spun by the Obama campaign as racist." Amid saturation media coverage, Ferraro resigned from Clinton's campaign, telling nbc News she wanted "to get this off the news."

Ferraro isn't the first presidential surrogate or adviser to take a fall this political season. Scrutiny of everyone representing the candidates has greatly increased, and criticism has mounted as each side seeks even the slightest advantage. Samantha Power, an Obama foreign-policy adviser, called Clinton "a monster" and resigned under pressure. Before the New Hampshire primary, Bill Shaheen, a prominent Clinton backer in New Hampshire and husband of Senate candidate Jeanne Shaheen, left Clinton's campaign after suggesting that the Republicans would pounce on Obama's admitted adolescent use of drugs if he were the Democratic nominee.

But it is the race issue that has deeply unsettled the Democratic contest and widened the troubling rift. In Mississippi, for example, Obama won 90 percent of the black vote and only one quarter of the white vote, a racial pattern that has persisted in several southern states. In other parts of the country, where Obama's share of the white vote has been much larger, racial divisions have not been as pronounced.

Dead heat. With 10 nominating contests left, including primaries in Indiana and North Carolina May 6 and West Virginia May 13, it's unlikely that either candidate can reach the 2,025 delegates needed for the nomination. About 800 "superdelegates"—elected officials, party leaders, and activists—could decide the outcome. They can vote however they want and aren't bound by the results of the primaries and caucuses. Many are holding back until they see who wins the most pledged delegates, states, and votes.

Another wild card is what happens to the delegates of Florida and Michigan. Those states violated party rules by holding their primaries too early, and the Democratic National Committee disqualified all 366 of their combined delegates. Clinton won both primaries, but Obama's name wasn't on the Michigan ballot, and neither campaigned actively in the two states. Now party leaders are trying to figure out a way to restore the states' delegates, possibly holding new primaries by mail, which would cost millions of dollars. A big sticking point is how to pay for it.

Some Democratic strategists are concerned that, unless things get patched up, the beneficiary will be John McCain, the Republican nominee who can point to disarray among the Democrats and argue that their party isn't able to govern itself, let alone the country. And the divisions could cause some Democrats to stay home in November if they believe their candidate was treated unfairly.