DES MOINES — DES MOINES -- Sen. Bob Dole grabbed the first major prize of the Republican presidential contest by a less than impressive margin last night, narrowly edging out a surging Patrick J. Buchanan in the Iowa precinct caucuses.
Former Gov. Lamar Alexander of Tennessee ran third and magazine publisher Steve Forbes a distant fourth. Voter turnout was unusually low, the result of a relentlessly negative campaign that turned off many voters, Republican leaders said.
Mr. Dole's victory was far from overpowering in a state where he is extremely well known, renewing doubts about the strength of his candidacy. Voters of Mr. Dole's generation, aged 65 and over, provided his margin of victory, according to a poll of caucus participants.
In nearly complete returns, the Kansas senator led Mr. Buchanan by 3 percentage points.
Mr. Buchanan, a commentator, solidified his claim as the candidate of the party's most conservative elements. He benefited from the low turnout, riding the support of dedicated anti-abortion activists and members of Iowa's powerful Christian conservative movement, who made one-third of all caucus participants.
In the Democratic caucuses, President Clinton was unopposed for renomination.
Last night's vote capped a long campaign marked by unprecedented spending on TV and radio advertising, much of it mean-spirited. Voter turnout was far below the predictions of party leaders, who blamed it on the nasty tone of the race.
Mr. Alexander, the former education secretary, appeared to be the principal beneficiary of voter revulsion over the way the race was conducted.
While Mr. Dole and Mr. Forbes were going negative, Mr. Alexander persuaded voters that he was running a largely positive campaign, even though he continued to run ads criticizing Mr. Dole and Mr. Forbes.
Besides the narrowness of Mr. Dole's victory, the biggest surprise was the poor showing of Mr. Forbes, who had to struggle to finish fourth, despite outspending the other candidates.
The political newcomer, who has been driving much of the action in the Republican race, had risen as high as second in polls in this state. But he wilted under a savage counterattack from Mr. Dole and the widespread criticism of his negative ad campaign from ordinary Iowans.
Sen. Phil Gramm of Texas finished fifth, and his candidacy seemed on the verge of collapse. Alan L. Keyes, the former Maryland Senate nominee, was a strong sixth, running close to Mr. Gramm and ahead of Sen. Richard G. Lugar of Indiana.
The narrowness of Mr. Dole's win puts added pressure on him in next week's primary in New Hampshire, where he lost to George Bush in 1988.
The Senate majority leader received about 26 percent of the Iowa vote, less than the 37 percent he got in winning a six-way race here in 1988. He also received 15,000 fewer votes than he received eight years ago. Voters interviewed at caucus sites criticized Mr. Dole for adding to the negative campaign atmosphere, and his top supporter in the state, Sen. Charles E. Grassley, said Mr. Dole had been hurt by the lower than expected turnout.
Dole aides contended that his performance was creditable, given the heavy assault he received from Mr. Forbes, whose ads painted the senator as a politician who could not be trusted to keep his word on taxes and other important issues.
"Thank you, Iowa. This is twice in a row," Mr. Dole told a cheering crowd of supporters at a downtown Des Moines hotel. "We withstood a barrage of millions and millions and millions of
dollars of negative advertising and came out on top."
"Tonight was the first big step on our road to return conservative common sense to the White House," he said, to chants of "Dole '96" from supporters, who traveled from throughout the Midwest to boost his chances here.
Mr. Buchanan, who overcame his lack of a strong campaign organization in this state, outran pre-caucus predictions with the strength of his support.
His impressive showing was a reflection of the strength of social conservatives in this state; in fact, his percentage of the vote was virtually identical to the 24 percent the Rev. Pat Robertson received in finishing second here in 1988. Among those who identified themselves as religious conservatives, Mr. Buchanan defeated Mr. Dole by better than a 2-to-1 margin.
Mr. Buchanan proclaimed his "incredible victory" at a hotel ballroom here, and boasted that he had run "hard on the heels of Bob Dole in the state he called his own."
Mr. Alexander, who badly needed a third-place finish to keep his underfinanced candidacy alive, said he had done it "the old-fashioned way," by spending 80 campaign days in the state, more than any other candidate.
"I thought Iowans would appreciate that more than the $4 million" Mr. Forbes is estimated to have spent on his intensive media campaign, he said. "Iowans really got turned off by all the negative campaigning."
Mr. Forbes, after taking a licking in his first real test as a candidate, sounded like a political veteran as he downplayed the significance of his disappointing performance.
"Despite relentless attacks in the last 10 days, we made a very credible showing tonight," he said, noting that he had spent only 18 weeks campaigning in Iowa, a state where his rivals have been courting voters for years.
However, his slide in the last week of the campaign suggested that many voters, having taken a second look at Mr. Forbes, decided to support other candidates or simply stayed home.
Mr. Gramm, who said last week that his candidacy would not survive a poor finish in Iowa, appeared headed for an early exit from the campaign. He could not hide his disappointment at a post-caucus rally last night, but his advisers said he intended to stay in the race.
The Texan had invested heavily in building one of the strong campaign organizations in the state. In August, he tied Mr. Dole in an Iowa straw poll, a success that proved to be the high point of his campaign.
Last night, Mr. Gramm was barely running ahead of the low-budget effort of Mr. Keyes, whose oratorical firepower won him a devoted following among the state's large number of Christian conservatives and anti-abortion activists.
The first showdown between Mr. Dole, an experienced veteran of four national campaigns, and Mr. Forbes, the newcomer, proved to be no contest.
Mr. Dole, from neighboring Kansas, played on his Midwestern roots and long political ties to this state to survive a bitter campaign that stunned longtime residents of Iowa, which prides itself on the cleanliness of its politics.
Fighting fire with fire, the Dole campaign outspent Mr. Forbes in the closing days of the race, launching a harsh counter-barrage that never let up.
A turning point, Dole campaign aides said, came about 10 days ago, after the senator's poll numbers had taken a beating from the relentless Forbes TV ad attacks. Senator Grassley, the state's most popular Republican and a close friend of Mr. Dole, made a plain-spoken endorsement spot.
Defending his old friend, Mr. Grassley condemned Mr. Forbes for his "vicious ads," called the businessman unqualified for the presidency, and endorsed Mr. Dole as "one of us," echoing the slogan of the senator's successful 1988 caucus campaign.
Iowa's 25 delegates to the Republican National Convention -- it takes 996 to be nominated -- won't be formally awarded until the state Republican convention in June, long after the nomination is expected to be decided.
Yesterday's official straw vote was nonbinding, but it has historically been regarded as the start of the nomination season. This year, Alaska and Louisiana jumped in front, with their first-ever caucuses.
Iowa, however, was the first state where all the GOP contenders took part.