John F. Kerry tapped freshman Sen. John Edwards of North Carolina as his running mate on Tuesday, calling his one-time rival for the Democratic nomination a politician of passion, middle-class values and clear conviction who can help the party "bring back our mighty dream" of a better America by ousting President Bush.

Kerry announced his decision at a downtown rally here Tuesday morning, describing Edwards as a man of courage and conviction who "has shown guts and determination and political skill in his own race for the presidency of the United States, a man whose life has prepared him for leadership and whose character brings him to exercise it."

Kerry, who kept his decision hidden until Monday evening from everyone but his wife, Teresa Heinz Kerry, informed Edwards of his selection during a 15-minute phone call around 7:30 a.m. "I was humbled by his offer," Edwards said in a statement, "and thrilled to accept it."

The announcement ended a long and secretive process in which Kerry and his team scoured through a list of about 25 names and consulted about 300 people before settling on the man whom many Democratic activists considered the obvious and most politically popular choice from the beginning.

Edwards, his wife, Elizabeth, and their children arrived here Tuesday afternoon to spend the evening with the Kerrys. The two candidates, once fierce rivals for the nomination, will make their first public appearance as the 2004 Democratic ticket Wednesday morning at the Kerrys' estate outside Pittsburgh.

Afterward, they plan to campaign in Ohio and Florida, two of the most populous and hotly contested battleground states, to rally voters with a message of prosperity and fairness at home and rebuilding U.S. credibility around the world. Kerry campaign aides said they hope to incorporate Edwards's populist message decrying "two Americas" -- one for the rich and another for everyone else -- and Kerry's broader themes into a potent call for change.

Edwards, 51, was a successful trial lawyer who made millions from his law practice before winning his Senate seat in 1998. During the presidential primaries, Kerry, 60, repeatedly questioned Edwards's qualifications for the presidency in private and in public, during and after the primaries. Aides said the presumptive nominee obviously no longer harbors such concerns.

Bush and Vice President Cheney gave Edwards a cordial welcome to the campaign, but the Bush campaign slammed the senator as an inexperienced leader unprepared to run the nation during a time of war and threat. It described the Democratic ticket as too liberal for mainstream America.

The Bush campaign also greeted Edwards with a television ad, titled "First Choice," that features Sen. John McCain (R-Ariz.) praising Bush as an unflinching wartime president. The ad is designed to suggest that Edwards was not Kerry's first choice.

Kerry considered McCain as a possible running mate, initiating a series of phone calls to the popular Republican during the spring about a unity ticket, but McCain made clear he was not interested.

James Johnson, a Washington businessman and Democratic veteran who conducted the running-mate search for Kerry, said on Tuesday that Kerry's outreach to McCain reflected his desire to restore some civility to the political debates in the country and that the dialogue "was well worth having." Johnson said Kerry considered other Republicans as well, but he declined to name them.

Kerry's campaign countered the Bush team by pointing to McCain's past praise of Edwards and by running its new ad in an effort to ride the wave of heavy news media coverage surrounding the decision. Posted online Tuesday night, the ad will begin airing on cable television networks on Wednesday. The ad marries the themes from the primary campaigns, with the narrator saying, "One is a combat veteran with over 30 years of experience handling the toughest issues facing America. The other is the son of a mill worker, who all his life has stood up for ordinary people against powerful interests. . . . Kerry/Edwards. A new team for a new America."

Cheney called Edwards to congratulate his new rival, but the pleasantries are likely to end there, as the GOP is preparing to relentlessly contrast the foreign-policy experience of the two vice presidential candidates. Several business groups, including the U.S. Chamber of Commerce, are also preparing anti-Edwards campaigns, condemning the former trial lawyer as hostile to businesses.

Still, the Bush campaign anticipates a big bump for the Kerry-Edwards ticket this month, which will culminate with the Democratic National Convention starting on July 26 in Boston, the presumptive nominee's home town.

Edwards, a boyishly handsome senator who was named by People magazine as the "sexiest politician" in 2000, is well-regarded inside the Democratic Party. Some Democrats say he has the campaign skills of Bill Clinton and the charm of a young John F. Kennedy.

He comes from humble origins, the son of a mill worker in the small town of Robbins, N.C., and he built his presidential campaign around the themes of economic and social injustice, particularly in states and communities dominated by Republicans in recent elections. Kerry and Edwards will campaign this weekend in North Carolina, including a stop in Robbins.

Kerry said his running mate "has honored the lessons of home and family learned in North Carolina and brings those values to this struggle to shape a better future for America."

Many Democrats see Edwards as an antidote to Kerry's serious and stiff style. "This is a ticket that can excite, motivate and most importantly defeat George Bush and Dick Cheney in November," Rep. Richard A. Gephardt (Mo.), whom Kerry had also considered as a possible running mate, said in a statement.

Strategists hope Edwards can boost the ticket in battleground states, among rural and suburban voters. Congressional Democrats predicted that the ticket will benefit the party's candidates across the board, especially in the South. Five southern Democrats are retiring from the Senate, and many candidates have been reluctant to embrace Kerry, but they are likely to be receptive to campaigning with Edwards.

Many Democrats had feared that Kerry might pass up his former rival, despite his obvious appeal within the party. For starters, there were questions about whether Kerry would select a running mate who has, in the words of one Democratic strategist, "luminescent" campaign skills, in contrast to Kerry's uneven performances.

Beyond that, they had worried that a perceived lack of personal chemistry would doom Edwards's chances, given their clashes in the primaries. This was such an obvious issue that Johnson, on the March day he was named to run the vice presidential search process, asked Kerry whether there was anything from the primaries or his Senate experience that ruled anyone out.

Kerry's reply, according to Johnson, was, "Absolutely not." Later, Johnson asked Kerry more directly about the reported tensions with Edwards, trying to gauge how much of an obstacle they might be. Once again, Kerry waved him off. "That was the campaign," Johnson recalled Kerry telling him.

If any candidate won a spot on a presidential ticket by actively campaigning for the job, Edwards is the classic example. When he dropped out of the presidential race, having won just one primary but lasting longer than any of Kerry's other main rivals, he instantly pivoted to become Kerry's most energetic surrogate.

"It had all the earmarks of a very carefully planned campaign," a longtime adviser to Edwards said. "There is nobody better at selling himself than John Edwards. He set out to sell himself to John Kerry and, once again, he's succeeded."

Johnson said that was not true, noting that at no time in the lengthy vetting process did Kerry evince any discomfort with Edwards's high profile. "It was absolutely not a problem," he said.

Edwards made the most of his popularity within the party. When Kerry had to turn down invitations to appear at Democratic conventions or meetings, his campaign team asked who the sponsors wanted as a substitute. Many asked for Edwards, who was almost always willing to take the assignment. As a result, he did far more than any of the other potential candidates. "It was a virtuous circle, where he was able to fulfill these demands and, as he performed, obviously at a very high level, he brought supporters as he went along," Johnson said.

He added that Kerry never felt pressured to take Edwards. "John always believed, and this is critical in the historical context, that he had full latitude, that it was really up to him, that it was not about counting noses, that it was not about interest groups," Johnson said.

Campaign officials said Kerry drew up a list of about 25 potential running mates and set Johnson and his team off to produce thick background papers on them. Johnson and campaign manager Mary Beth Cahill met with Kerry about every 10 days to discuss the choices and to gather more information.

Kerry, burned by his experience as a vice presidential contender four years ago, insisted on privacy, and the campaign never leaked a short list of candidates. Johnson said that as late as Thursday, he and Kerry were discussing candidates who had not been named for weeks in news accounts. Among those in contention were Gephardt, Iowa Gov. Tom Vilsack and Sen. Bob Graham (Fla.), but Johnson said they were not the only ones in the mix at the end.

Kerry met secretly with many of the contenders, and it is believed Edwards spent more time in direct conversation with Kerry and his search team than anyone else. On Tuesday morning, after asking Edwards to be on the ticket, Kerry called those whom he did not select, but neither Johnson nor Cahill would say who or how many were called.

Last Thursday, Edwards was flown from Florida to Washington for a late-night meeting. Kerry spent the weekend mulling his decision while on a bus tour of the Midwest. He informed Johnson and Cahill during a late-night dinner of fish soup and salad late Monday night.

Kerry was so secretive about the process that the second person he told of his decision was the man hired to paint "Kerry-Edwards" on the side of the campaign plane. Kerry called the decal applier, who had signed a confidentiality agreement, at 6:30 p.m., more than three hours before he told Cahill and Johnson.

In a sign of the times, Kerry then announced his pick via e-mail to more than 1 million supporters. With Edwards on board, Kerry is expected to soon top a once-unthinkable $200 million in contributions. He and Edwards are planning to attend fundraisers in New York on Thursday night and Friday morning.

Balz reported from Washington. Staff writers David S. Broder and Howard Kurtz contributed to this report.

After accepting the No. 2 spot on the Democratic ticket, Sen. John Edwards leaves Washington with son Jack and daughter Emma Claire, followed by wife Elizabeth and other daughter Cate. They joined Sen. John F. Kerry and his family near Pittsburgh.Sen. John F. Kerry (D-Mass.) greets supporters during a rally in downtown Pittsburgh, where he announced his choice of running mate.Sen. John Edwards (D-N.C.) accepts the cheers of well-wishers at the Pittsburgh airport, before he joined the Kerrys at their estate.