Bernie Sanders narrowly won New Hampshire's Democratic presidential primary on Tuesday, solidifying his front-runner status in the White House race and dealing a setback to moderate rival Joe Biden, who finished in a disappointing fifth place.Moderate Pete Buttigieg, the 38-year-old former mayor of South Bend, Indiana, finished a close second after edging out Sanders in last week's chaotic and disputed first nominating contest in Iowa. Both campaigns have asked for a partial recanvass of Iowa results. Sanders, a progressive senator from neighboring Vermont, prevailed after fending off attacks from rivals who warned his far-left views would lead the party to defeat in the Nov. 3 election against Republican President Donald Trump."This victory here is the beginning of the end for Donald Trump," Sanders told supporters in Manchester, New Hampshire.Sanders' supporters booed when Buttigieg's post-primary speech was shown on screens, and chanted "Wall Street Pete."It was also a good night for Senator Amy Klobuchar, who rode a wave of momentum from a strong debate on Friday into a third-place finish.Biden, the former vice president who was once the front-runner in the Democratic race, limped to his second consecutive poor finish after placing fourth in Iowa. He is certain to face growing questions about his campaign's viability and his ability to consolidate moderate support against a surging Buttigieg and Klobuchar.Biden fared poorly in two previous runs for president before winning election in 2008 as President Barack Obama's No. 2. He hopes to stay afloat this time until the Feb. 29 contest in South Carolina and a series of contests in other Southern states on Super Tuesday on March 3, where his support among African Americans will be a strength.Without strong showings there, his race could be over.'IT AIN'T OVER'"It ain't over, man. It's just getting started," Biden told supporters in South Carolina.U.S. Senator Elizabeth Warren, a progressive ally of Sanders who was considered a favorite in New Hampshire three months ago, also had a bad night. She finished fourth, and also will face questions about her continued viability.For Sanders, who won New Hampshire in 2016 with 60% of the vote against eventual nominee Hillary Clinton, the results offered new momentum but not the overwhelming win he had hoped for given his history in the state. Exit polls showed he only won about two-thirds of his 2016 primary supporters.The results began to thin the field of Democrats seeking the right to take on Trump in November, with businessman Andrew Yang and Senator Michael Bennet dropping out after it became clear they would finish well out of the running. CBS News reported that Deval Patrick, the former Massachusetts governor, would drop out on Wednesday.Democratic voters in New Hampshire chose a candidate from a ballot with 33 names, including those who dropped out weeks ago. But it did not include former New York Mayor Michael Bloomberg, a billionaire who is not competing in any states before the 14 Super Tuesday primaries on March 3.Bloomberg has been rising in polls, aided by his massive personal spending on campaign advertising, and is betting on doing well in bigger states such as California and Texas.In New Hampshire, turnout was approaching the record 287,000 who cast ballots in the 2008 New Hampshire Democratic primary, when the battle between Barack Obama and Hillary Clinton energized the party. That could ease Democratic concerns about the smaller-than-expected turnout in Iowa last week.Democrats in New Hampshire and in the other states that will vote in the state-by-state battle for the Democratic nomination are trying to decide whether they want to pick a moderate like Buttigieg, Klobuchar, Bloomberg or Biden, or progressive leaders like Sanders and Warren, who represents neighboring Massachusetts.MORE DIVERSE BATTLEGROUNDS AHEADAfter Iowa and New Hampshire, small and rural states with predominantly white populations, the race will move on to more diverse battlegrounds that pose new tests.Up next will be the Feb. 22 caucuses in Nevada, which has a large Latino population, and the Feb. 29 primary in South Carolina, which has a large African-American population."We have beaten the odds every step of the way," Klobuchar told supporters in Concord, New Hampshire. "Because of you, we are taking this campaign to Nevada. We are going to South Carolina. And we are taking this message of unity to the country."Warren said it would be a long, drawn-out battle for the nomination and the race was far from over. She decried the party's infighting and called for unity as the contest moves on."These tactics might work if you're willing to burn down the party to be the last man standing," Warren said. "We win when we come together."The late attacks on Sanders in recent weeks were a shift in tactics for his rivals, who had mostly ignored him out of worry about a backlash from his fervent cadre of supporters and out of doubts that Sanders could expand his base.Buttigieg, who would be the first openly gay U.S. president if elected, still faces questions about what polls show is his weakness with African-American voters, one of the most loyal and vital Democratic voting blocs.He also decried the growing polarization of politics and the Democratic infighting of recent weeks."In this election season, we’ve been told by some that you must either be for revolution or you are for the status quo. But where does that leave the rest of us?" Buttigieg asked supporters in Nashua, New Hampshire."A politics of my way or the highway is a road to re-electing Donald Trump," he said.On the Republican side, Trump easily won the state's presidential primary, defeating rival William Weld, the former governor of neighboring Massachusetts.