No finding from the surveys of voters as they left polling places Tuesday was more chilling to Democratic leaders than this one: Fewer than half of Clinton supporters in Indiana and North Carolina said they would vote for Obama in November if he is the party's nominee. More than a third said they would back McCain; one in 10 vowed to stay home.
Massachusetts Sen. John Kerry, an Obama supporter and the party's 2004 nominee, says the findings simply reflect "the heat of the moment," but Democratic veteran Simon Rosenberg isn't so sure. "Everybody in the Democratic family knows today that it's going to be hard to put this party back together," says Rosenberg, president of a Democratic think tank called NDN.
Feelings may be heightened because of the groundbreaking nature of both campaigns. Obama would be the first African-American nominated by a major party for president; Clinton the first woman. "The question really is whether identity politics becomes more important than partisan politics," political scientist Steven Schier of Carleton College says. "Do you get so upset that a member of your group is not being nominated that you abandon your party?"
•Stop playing defense.
Obama has seemed embattled for a month or more, forced to explain his comments about small-town Americans who "cling" to guns or religion and to distance himself from inflammatory comments by his former pastor, Jeremiah Wright. Clinton seized on Obama's opposition to a temporary moratorium on the federal gas tax as proof he doesn't understand or stand with working America, painting him as an elitist.
"This might be seen, when we look back, as a critical moment at which Obama was very badly damaged," says Bill Lunch, a political scientist at Oregon State University. (Obama campaigns Friday and Saturday in Oregon, which holds its primary May 20.)
Obama has responded by campaigning more often at diners and on factory floors. On Tuesday night, he cast his campaign as motivated by helping working people such as an Indiana woman who lost her pension when her employer moved a manufacturing plant overseas, and a Pennsylvania man who needed a new job but couldn't afford the gas needed to look for one. "This election is about you," Obama said.
The contentious campaign has made Obama a more nimble candidate who has gotten some practice responding to accusations that almost certainly will be repeated in the fall. "Better that Obama deal with these things now and get some footing on them than have them come out of left field in October," says Joe Trippi, who managed Howard Dean's presidential campaign in 2004.
•Turn the focus on McCain.
In his victory speech, Obama referred to Clinton only in passing, but repeatedly railed against McCain and those on "the other side" for "failed policies of the past."
Whatever the challenges ahead, the Democrats have a political landscape tilted in their favor. Voters are opposed to the Iraq war, alarmed about the weak economy and convinced the country is headed in the wrong direction.
"If the Democrats can't win with this deck of cards, I'm not sure we should win," says Mark Siegel, a former official of the Democratic National Committee.
Still, McCain campaign manager Rick Davis sent out a memo Wednesday touting McCain's strength among independents and crossover Democrats. "Data to date suggest Democratic Primary voters will not blindly support Senator Obama," he wrote. McCain, meanwhile, campaigned in Michigan.