PORTSMOUTH, N.H. — After 14 months of policy clashes and moments of mutual disdain, Bernie Sanders endorsed Hillary Clinton for the Democratic presidential nomination on Tuesday, clearing away the last major obstacle to a united Democratic front heading into the party’s convention this month and the general election this fall.
Entering the high school gymnasium together and waving and shaking hands along the rope line and from the stage, Mrs. Clinton and Mr. Sanders stood before a giant American flag image flanked by Mrs. Clinton’s motto, “Stronger Together.” They appeared to chat briefly before Mr. Sanders spoke, and he patted her on the back before Mr. Sanders stepped forward to cheers to “Unity!”
“Secretary Clinton has won the Democratic nominating process,” Mr. Sanders said, as cheers erupted and Mrs. Clinton broke into a wide smile. “And I congratulate her for that. She will be the Democratic nominee for president, and I intend to do everything I can to make certain that she will be the next president of the United States.”
“I have come here to make it as clear as possible why I am endorsing Hillary Clinton and why she must become our next president.”
Mr. Sanders, the fiercely independent senator from Vermont, who portrayed Mrs. Clinton as a captive of big-money interests during their race, was in a bittersweet but resolute mood, according to Sanders advisers, as he took the stage with her at Portsmouth High School. He was back in a state that once filled his campaign with hope, after he crushed Mrs. Clinton by 22 percentage points in the February primary, and he came around grudgingly to supporting her, the advisers said. But he was also determined to make a strong case against Donald J. Trump, the presumptive Republican nominee, and to champion Mrs. Clinton as the only chance to defeat him.
Whether Mrs. Clinton can also win over the 13 million Sanders voters will be one of her biggest challenges at the convention July 25-28 in Philadelphia and in the weeks ahead. About 85 percent of Democrats who backed Mr. Sanders in the primary contests said they planned to vote for her in the general election, according to a Pew poll released last week. Yet she has struggled to appeal to the independents and liberals who rallied behind the senator’s call for a “political revolution” to topple establishment politicians, Mrs. Clinton included.
When Mr. Sanders finished his remarks, he and Mrs. Clinton had a tight hug. “You were great, so great,” Mrs. Clinton said to him. “Thank you so much.” Then, in her own speech, she thanked him profusely and hailed Mr. Sanders’s wife, Jane, while also reaching out to his supporters.
“With your help, we’re joining forces to defeat Donald Trump, win in November, and build a future we can all believe in,” Mrs. Clinton said. “Thank you, thank you Bernie for your endorsement, but more than that, thank you for your lifetime of fighting injustice. I am proud to be fighting alongside you because, my friends, this is a time for all of us to stand together.”
Mrs. Clinton is counting on Mr. Sanders to help bring his supporters into her camp, and Sanders advisers said he would try. In a text message on Tuesday before this campaign event, Michael Briggs, a spokesman for Mr. Sanders, said the senator and his wife feel as if their voters should feel encouraged.
“They feel like the millions of people who were the heart and soul of the campaign have a lot to be proud about,” Mr. Briggs wrote as he drove from Vermont with Senator Sanders and Ms. Sanders to the New Hampshire event.
One person close to Mr. Sanders said the senator and his wife were “putting on a good face” Tuesday but were disappointed that his campaign did not succeed after he gave it so much of his energy and rallied millions of people around his ideas. The person, a longtime top political adviser to Mr. Sanders who spoke on condition of anonymity to share the private views of the couple, also said the senator was resolved to keep his word that he would endorse the Democratic nominee and that he has been told by some high-ranking Democrats that he could become chairman of the committee that will work on trying to carry out a proposed $15 federal minimum wage.
Denouncing Mr. Trump as much as praising Mrs. Clinton, Mr. Sanders unfurled an aggressive, point-by-point comparison of the policy positions of the two candidates, arguing that “there is no doubt in my mind that, as we head into November, Hillary Clinton is far and away the best candidate.”
Largely blurring over his own differences with Mrs. Clinton, Mr. Sanders aligned himself with her on creating more jobs, raising the minimum wage, expanding access to government-run health care, combating climate change, and offering relief to college students in deep debt. But he made no mention of new regulations on Wall Street and his disgust for billionaire-driven “super PACS,” two points on which he hammered Mrs. Clinton during their long nomination fight.
“It is no secret that Hillary Clinton and I disagree on a number of issues — that is what this campaign has been about, that is what democracy is about,” Mr. Sanders said.
He left it to Mrs. Clinton to promise aggressive action to police greed on Wall Street and overhaul the campaign finance system.
“It is past time to end the stranglehold of wealthy special interests in Washington,” she said as Mr. Sanders smiled and clapped. Still, she did not promise to forego major donations herself: After the event she planned to fly to New York for a private matinee performance of the hit Broadway musical “Hamilton” for donors who gave $2,700 to $100,000 to her campaign or the Democratic National Committee.
On the campaign trail, Mrs. Clinton has been focused on winning over independents and Republican-leaning women who are turned off by Mr. Trump, exuding confidence that the young voters and liberals who backed Mr. Sanders would get in line and support her when faced with the prospect of a Trump presidency instead.
But behind the scenes, her senior campaign aides have tried to build bridges to a wing of the party skeptical of Mrs. Clinton and the brand of centrist politics her husband advanced. Since she clinched the number of delegates needed to secure her party’s nomination on June 7, the campaign has reached out to Mr. Sanders’s supporters, dispatching the campaign manager Robby Mook, the director of states and political engagement, Marlon Marshall, and the top policy adviser Jake Sullivan, to states where Mr. Sanders defeated Mrs. Clinton, including New Hampshire, Wyoming, Vermont and Washington State.
The détente between the two camps began after Mrs. Clinton and Mr. Sanders met privately at the Hilton in Washington last month. Jeff Weaver, Mr. Sanders’s campaign manager, and Mr. Mook remained behind after the meeting hashing out their differences and discussing policy for the next two hours. In the weeks that followed, Mr. Mook, a Vermont native, and Mr. Weaver were in daily contact, exchanging texts and phone calls and grabbing dinner at the Farmhouse Tap and Grill in Burlington.
Mrs. Clinton also inched toward Mr. Sanders’s positioning on education, with a pledge to make public colleges and universities tuition free for families that make less than $125,000 a year and with a reaffirmation of a “public option” to be built into the Affordable Care Act.
In Orlando, Fla., Mrs. Clinton’s policy adviser, Maya Harris, and Mr. Sander’s policy adviser, Warren Gunnels, sat down to come up with compromises on both issues, though trade and the Trans-Pacific Partnership deal, in particular, remains a sticking point between the two camps.
For many Sanders supporters, voting for Mrs. Clinton is still hard to fathom: Recent polls show that only a small fraction of them would support her enthusiastically. At the campaign event here, as well as around the country, there was a relatively lukewarm reception for Mrs. Clinton among the legions of liberals who embraced Mr. Sanders’s attacks on her ties to Wall Street and previous support for global trade deals.
Ethan Winnett, 31, of Waukegan, Ill., said Mr. Sanders might be being “duped” or “threatened” by Mrs. Clinton and vowed never to vote for her even if she’s back by the senator. The computer engineer believes Mrs. Clinton is “more crooked than Trump” and said he felt “betrayed” by Mr. Sanders’s endorsement.
Mr. Winnett added that he also feels betrayed by Senator Elizabeth Warren of Massachusetts and President Obama for their support of Mrs. Clinton. In his frustration with the race, he has already turned to working for the Green Party and this summer helped collect signatures to get the party’s presidential nominee, Jill Stein, on the ballot in Illinois.
However, Winnie Wong, co-founder of People For Bernie, said the group will now be focusing efforts on explaining to people the damage a Trump presidency could do. The group, though, will not be endorsing Mrs. Clinton, she said.
“This is what I expected to happen,” Ms. Wong said of Mr. Sanders’s endorsement. “I will do what I can to stop Trump. We cannot afford a Donald Trump presidency and I think most people from social movements understand that.”
Mr. Sanders’s endorsement comes after weeks of talks between his campaign and Mrs. Clinton’s and after a tough primary battle where he frequently attacked her as not being progressive enough. He often criticized Mrs. Clinton as the “anointed candidate” and assailed her for her ties to Wall Street, for having a “super PAC,” for not more strongly backing an across-the-board $15 minimum wage. He called on her repeatedly to release transcripts of her paid speeches to commercial banks.
Mrs. Clinton attacked Mr. Sanders’s past tepid support of gun control, implicitly tying him to gun violence. His defense – that he represented a state with a hunting population – did little more than remind voters that his entire career had been spent in the removed idyll of Vermont.
Frustrated, Mr. Sanders, at a rally in Philadelphia in early April, called Mrs. Clinton “unqualified” to be president, setting off days of back and forth between the campaigns.
“She has been saying lately that she thinks that I am, quote unquote, not qualified to be president,” Mr. Sanders said then. “I don’t believe that she is qualified if she is, through her ‘super PAC,’ taking tens of millions of dollars in special interest funds.”
Such language, according to Sanders advisers, would certainly not be part of the speech that Mr. Sanders had written by hand for Tuesday’s endorsement event in New Hampshire.