PHILADELPHIA, April 22 -- won the Pennsylvania primary Tuesday night, a victory that gave her candidacy a lift and moved the race for the Democratic presidential nomination into a two-week sprint to potentially decisive contests in Indiana and North Carolina.
Sen. Barack Obama (Ill.), anticipating defeat despite outspending Clinton by 2 to 1 in Pennsylvania, flew to Indiana for a rally before the polls had closed. Clinton's margin of victory was not clear shortly after polls closed in the state.
After nearly a year and a half of campaigning, four months of caucuses and primaries, and millions of ballots cast, the Democratic nomination remained not only up for grabs but also a source of increasing strife for the party.
Although Obama continues to hold a massive financial advantage and a lead in pledged delegates that will be almost impossible for Clinton to surpass in the dwindling number of remaining contests, the senator from New York said she is determined to stay in the race until the final primary votes are cast on June 3 and showed no sign she planned to ease her assault on Obama.
Throughout the seven-week contest in Pennsylvania, party leaders watched nervously as the two Democrats engaged in an increasingly divisive campaign that culminated in a exchange of negative television ads over the final weekend.
The final hours of the Pennsylvania contest had something of an anticlimactic feel as the two campaigns debated what kind of margin Clinton would need to win in order to claim momentum heading into the next round of voting.
Her campaign hoped a resounding victory would help move undecided superdelegates, a group of several hundred party leaders and officeholders who are likely to determine the eventual nominee, into her column. Clinton's closing argument in Pennsylvania resembled her core rationale for running in the first place She said she was best able to beat Sen. John McCain (R-Ariz.) in the general election, most qualified to serve as commander in chief and uniquely suited for the presidency based on her life experiences. She ran an ad invoking Harry S. Truman, challenging her rivals to get 'out of the kitchen' if they couldn't stand the heat that came with a campaign for the White House. The Obama campaign said the ad was an attempt to inject scare tactics into the race, noting the use of an image of Osama bin Laden in the spot.
Clinton pegged her long-shot hopes of derailing Obama on Pennsylvania, a state where she spent summers as a child in her father's hometown of Scranton and where key demographics -- whites, working-class voters and Catholics -- exist in sizable enough numbers to make a landslide seem within reach.
The Obama campaign, by contrast, downplayed its chances in Pennsylvania from the start, although polls had showed the candidate steadily closing a gap that was as large as 20 points at the outset.
What little momentum Obama seemed have appeared to stall about 10 days before votes were cast, when news broke of his comments about 'bitter' small town residents who 'cling' to guns and religion because Washington has let them down.
The remarks, taped during a San Francisco fundraiser, forced Obama to play defense for nearly a week. Just as he appeared to be regaining his footing, he struggled through a debate with Clinton in Philadelphia after being hit with a series of tough questions including why he doesn't wear flag pins and his relationship with a former member of the radical group the Weather Underground.
With the primary less than a week away, Obama was again forced off message. He campaigned through the state aggressively, hitting all four corners and much of Pennsylvania's conservative heartland.
Usually accompanied by his highest-profile backer in the state, , he visited local bars, factories and bowling alleys and held smaller town hall meetings instead of big rallies, seeking to neutralize Clinton's support in individual congressional districts to limit her take of pledged delegates.
His weekly ad spending topped $3 million, for a total of around $12 million in the campaign there. Voters appeared to be paying close attention. Obama drew his biggest crowd of the campaign Friday night in downtown Philadelphia, with 35,000 people stretching over three city blocks.
Obama's rhetoric about Clinton also became increasingly aggressive in recent days. He raised questions about her honesty and integrity, devoting at least a third of his stump speech to a point-by-point critique of her ties to special interests, her stance on issues including trade and Iraq, and her 'slash-and-burn' campaign tactics. It was a risky move by Obama, potentially undermining his commitment to a different kind of politics. But his advisers said they thought he had been burned in previous contests by not forcefully answering Clinton's charges about his inexperience.
Yesterday morning he had a pancake breakfast at a Pittsburgh diner with Steelers owner Dan Rooney, packed in local radio and television interviews, and stopped by a famous cheesesteak restaurant in south Philadelphia, along with a barbershop on the mostly African-American west side of town.
All day Tuesday, Obama and his advisers sought to lower expectations, calling the state a Clinton stronghold that she was always expected to win easily. The campaign circulated a memo yesterday morning that lowered the bar for Obama and raised it for his opponent. 'Pennsylvania is considered a state tailor-made for Hillary Clinton, and by rights she should win big,' the memo read. 'She has family roots in the state, she has the support of the Democratic establishment -- including Governor Rendell's extensive network -- and former President Clinton is fondly remembered.' Ahead of time, Obama resisted parsing the Pennsylvania results. 'Let me cut to the chase,' he told reporters at Pat's King of Steaks. 'A win is fifty plus one. So if Sen. Clinton gets over 50 percent, she's won the state. I don't try to pretend I enjoy getting 45 percent and that's a moral victory.' It also was a concession to a reality that the Obama campaign conceded long ago, that Clinton would be toughest to beat in the big Northeast states because of their large populations of white, working-class Democrats, her core supporters. For Obama, Pennsylvania represented the last of the big-state hurdles in a race he now believes will continue until Montana and South Dakota hold the final primaries on June 3. 'I've come to conclude that this race will continue until the last primary or caucus vote is cast. That's not that far away,' Obama told reporters earlier in the day in Pittsburgh.
Staff writer Paul Kane, traveling with Obama in Pennsylvania, contributed to this report