SAN DIEGO (AP) _ In the proudest moment of his long political life, Bob Dole claims the Republican presidential nomination tonight and launches a campaign against President Clinton on the themes of character, leadership and hefty tax cuts.

``We're going to win this campaign, we're going to win on Nov. 5, 1996,'' Dole declared after the convention's roll call of states awarded him the nomination in a frenzy of sign waving and confetti throwing.

``Now, as Bob becomes the official nominee, we'll be able to get our message out,'' his wife, Elizabeth, said in an interview broadcast today on ABC's ``Good Morning America.''

Mrs. Dole blamed lack of money following a ``feisty primary season'' for Dole's low showing in the polls, a situation she expects to change now that the main campaign is under way.

But longtime opponent Pat Buchanan cautioned that Dole's acceptance speech could, in effect, make or break the campaign.

``The senator has an opportunity there to define himself to the American people, many of whom don't know who he is. ... It could set his campaign on the road toward victory or it could be very, very difficult if things didn't go very well,'' Buchanan said on ``Fox Morning News.''

Running mate Jack Kemp pledged to his disabled boss: ``I'm going to be Bob Dole's right arm, I'm going to be his right hand.''

Battling to overcome Clinton's persistent lead, the plain-spoken Kansan closes the convention with a prime-time speech before the largest audience of his life. The closely guarded 40-minute address, four months in the making, was rewritten right up to the end.

One major debate was whether Dole should mention his opposition to abortion, or Clinton's veto of legislation banning certain late-term abortions. Dole ultimately decided against the idea.

Delegates said they hoped to hear Dole speak tonight with passion and compassion.

``He needs to reaffirm what he stands for and be enthusiastic about his program,'' said Cleo Atkins, vice chairwoman of the Idaho delegation. ``He has to show how much he cares. He needs to show his passionate side.''

``We have the enthusiasm and we're in better shape than the polls show,'' said Denise McNamara, an alternate delegate from Dallas.

It will be a night of political excitement but no suspense. Balloons will cascade from the ceiling and rise from the floor, with the help of helium. A seven-minute campaign video will present images of Dole's boyhood in the small town of Russell, Kan., during the Depression, his struggle as a disabled veteran and his rise to power in the halls of Congress.

And once more, the man who served 35 years in Congress _ and longer than anyone else as Senate Republican leader _ will attempt to define his national vision and generate excitement about his candidacy.

Dole faces a difficult road to the White House.

Traditionally, Americans are reluctant to evict an incumbent who can boast that the nation is at peace, the economy is expanding and jobs are growing. The electoral map and polls showing concern about Dole's age _ he's 73 _ suggest he needs a comeback of historic proportions.

In fact, several hundred convention delegates _ asked to look ahead four years _ said they would favor Kemp as the GOP's presidential nominee if Dole was defeated this year or did not run in 2000. In an Associated Press canvas of 1,293 of the 1,900 delegates, Kemp was the choice of 557 delegates.

The centerpiece of Dole's campaign is an economic package promising to cut the income tax rate 15 percent across-the-board, slash the capital-gains tax rate by half and award lower and middle-income families a $500-per-child tax credit.

The White House calls the program a budget-busting nightmare.

Republicans tried to give Dole a strong sendoff as they delivered the nomination Dole has sought for 16 years.

``Tonight we ask Bob Dole to answer his country's call again and stand a post for America _ the first post of the land _ not for his sake, but for ours,'' said Arizona Sen. John McCain.

``Others may offer you sound bites and showmanship,'' McCain declared. ``But Bob Dole offers you leadership _ leadership evident in the stature of a man who risked his life for love of country, and considers service to America his honor.

``We're on the map!'' exclaimed Dole, seeming to fight back tears as McCain put his name in nomination. Dole watched by television with Kemp in a 33rd floor hotel suite.

Former Secretary of State James A. Baker III said Clinton's administration had been ``four years of flip flops and photo ops.''

Accusing Clinton of indecision and drift, Baker said, ``When they write the history of Bill Clinton's foreign policy, they're going to call it Gullible's Travels.''

The Clinton campaign shot back with sarcasm about Dole's tax-cutting program.

``Which Bob Dole will show up (tonight) _ the Bob Dole who for 35 years fought budget deficits or the Bob Dole who last week was converted to supply-side economics?'' asked Clinton campaign press secretary Joe Lockhart. Democrats distributed a 13-page critique of Dole's legislative record, calling him ``Beltway Bob.''

Wednesday night's nominating roll call of the states ran long, well past midnight in the East.

When the Kansas delegation put Dole's nomination over the top, Dole declared, ``All right.'' He stood up, hugged his wife, Elizabeth and reached out to shake the hand of his campaign manager, Scott Reed. ``We made it, Scott.''

Mrs. Dole watched television with Dole, curled up on the floor at his feet. Earlier, she delighted delegates with an unprecedented stroll on the convention floor with testimonials for her husband.

She called Dole ``my own personal Rock of Gibraltar'' and warned him she might say some things that her famously reticent husband ``would never be willing to talk about.''

Back in his hotel room, Dole approved of her speech. ``I think I'll let her give mine tomorrow night,'' he deadpanned.