Robert D. Squier, 65, a leading political analyst and campaign consultant who advised Presidents Clinton and Carter on election strategy and who also helped put Democratic senators and governors in office, died of colon cancer Jan. 24 at his home in Millwood, Va.

Mr. Squier was a longtime friend and confidant of Vice President Gore and had played a pivotal role in helping Gore win two elections as senator from Tennessee. He traveled frequently with the vice president, whom he had counseled before speeches and debates. Until shortly before his death, he was a member of Gore's media team in the vice president's quest for the Democratic presidential nomination. But in recent months his influence in the Gore hierarchy had been reduced.

As a charter member of the fraternity of professional political consultants, Mr. Squier was an innovator in the use of the filmed 30-second television commercial. His firm--Squier, Knapp & Dunn Communications--was said to have been among the top Democratic political advertising agencies in the nation.

In a statement from the White House, Clinton said: "Bob was not only a valued adviser, but more importantly, he was our friend. His loyalty, talent, and above all, his perseverance helped Vice President Gore and me craft a winning re-election campaign when many had counted us out."

Clinton added that "Bob was a pioneer in the art of political communications. With his documentary films, his path-breaking political commentary and his work for progressive candidates, Bob helped make policy and politics understandable and exciting for millions of Americans."

In 1968, Mr. Squier got his start in politics when President Lyndon B. Johnson invited him to the White House and asked him to be his television adviser. He had barely accepted the position when Johnson withdrew from the presidential race.

But Mr. Squier stayed around to help in the campaign of then-Vice President Hubert H. Humphrey. He discovered that he preferred partisan filmmaking to the work he had been doing previously with public television and the United States Information Agency.

Four years later, he signed on with Sen. Edmund S. Muskie (Maine) in Muskie's quest for the Democratic presidential nomination, then consulted with the Carter campaign in 1976. He helped elect Democrats Christopher J. Dodd (Conn.), John D. "Jay" Rockefeller IV (W.Va.) Dale Bumpers (Ark.) Tom Harkin (Iowa), Paul Simon (Ill.), Gary Hart (Colo.), Robert C. Byrd (W.Va.) Joseph R. Biden Jr. (Del.), Bob Graham (Fla.) and Charles S. Robb (Va.). He also helped elect Richard C. Shelby of Alabama, who later became a Republican.

"I came to politics out of the frustration that a lot of people felt who were filmmakers in the '60s," Mr. Squier told The Washington Post in 1985. "You were sent out to do a show on civil rights, and it wouldn't take you 15 minutes to figure out what the story was. But you had to come back with, quote, 'both sides.' You found yourself interviewing segregationists about why their arm hurt so much after beating up on blacks. To work in politics is a chance to work for people you really care about and take what you know about television and put it right at someone's service."

In the late 1970s and through the 1980s, Mr. Squier was arguably the dominating figure in the field of political consulting, known for creative, imaginative and effective advertising. He was a campaign adviser to Maryland governor Marvin Mandel (D), and he helped Robb win the Virginia governorship with an advertisement that projected a tough-guy image by showing him firing a pistol and emphasizing his Marine Corps service during the war in Vietnam.

To get Graham elected governor of Florida, Mr. Squier devised a plan that had the candidate doing a workingman's "workday" in 100 different jobs, including chicken plucker, herder of dairy cows and bellhop. "Bob Graham--working for governor" was the campaign slogan. There were complaints that this was pure political gimmickry, but it worked, Graham was elected, and Mr. Squier repeated the tactic elsewhere in other campaigns.

"In this business, you're kind of really judged by the number of wins you have by your name, and no one had more than him," said fellow consultant and Clinton adviser James Carville. "He was to political consulting what Hank Aaron was to home runs."

During the last decade, Mr. Squier's luster was said to have dimmed, but friends and aides bristled at suggestions that he might have lost his touch. His candidates lost some key races, including the 1994 Texas governorship in which he advised the Democratic incumbent, Ann Richards, in her contest with George W. Bush. A Bush consultant in that campaign told the Austin American-Statesman newspaper that Richards's ads were "tired, worn, hackneyed overreaching. Bob Squier has failed to portray her at her natural best--thank God."

There were times when he was accused of crossing the lines of ethical propriety.

In 1990, one of Mr. Squier's spots charged that a gubernatorial candidate in Massachusetts was "plagued by questions about his corruption record"--the questions were about the candidate's record in prosecuting official wrongdoing. Another of Mr. Squier's spots accused a Michigan candidate of voting "to let dangerous criminals out of state prisons early," even though Mr. Squier's client had put the same early-release program into effect.

Last July, Mr. Squier's influence in the Gore presidential campaign was reduced when Carter Eskew, an estranged former business partner and protege of Mr. Squier's, joined the vice president's circle as a media strategist. Eskew and Mr. Squier had a bitter falling out over issues related to their shared consultancy a half-dozen years earlier, and the bad blood generated headlines when they were brought back together.

Mr. Squier was born in Brainerd, Minn., and graduated from the University of Minnesota. As a college student, he did his first television commercial for Democrat Orville Freeman, the Minnesota governor who later became secretary of agriculture.

After college, he worked in public television in Texas and New York, then came to Washington as a film specialist with USIA and later as an executive producer with National Educational Television. Throughout his career as a political consultant, he continued to work on documentaries, and he won awards for films on William Faulkner and Herman Melville. At his death, he was working on a piece about Ernest Hemingway.

Glib, perpetually tanned and engaging, Mr. Squier was known on the campaign trail as a master of the one-liner who always knew how to find the finest restaurants with the best wine lists. In the early 1980s, he moved from his town house on Capitol Hill to the Virginia countryside, where he grew grapes and tended a wine press.

When Bill Clinton picked Al Gore as his vice presidential candidate in 1992, Mr. Squier is said to have told the Arkansas governor that "he'll never stab you in the back, even though you may deserve it."

In a 1993 interview with Campaigns and Elections magazine, he looked back on his years as a political consultant. "The business has changed enormously, particularly in the area of research," he said. "We now know more about our candidates and our opponents than we ever did in the past. . . . The consultants who are most serious in the business really know what they are talking about before they even begin to think about their first commercials.

But he added, "the candidate is always more important than the consultant. The consultants that do poorly in this business are the ones who begin to forget that."

His marriage to Jane McNeely ended in divorce.

Survivors include his wife, Prudence Bergman of Millwood; two sons from his first marriage, Mark Ralph Squier and Robert McNeely Squier, both of Bethesda; and three grandchildren.

CAPTION: Robert D. Squier was praised by President Clinton as a "pioneer."