Sen. Lowell Palmer Weicker, the most morally indignant of the old Senate Watergate investigators, today became what he called "the longest shot in the field" for the Republican presidential nomination.

The 47-year-old Connecticut Republican did so with the same quixotic style that has baffled and outraged his friends and foes alike for years.

Within hours of his announcement at the Old State House here, the 6-foot-6 Weicker insulted most members of his party, accused its leaders of trying to "bury me," called former president Ford unimaginative and said his competitors for the GOP nomination weren't worth bothering to talk about.

"We've sort of excluded all the normal people from the [Republican] party," Weicker told a television interviewer. "There is only a handful of us left."

Brushing aside most of what is considered conventional political wisdom, Weicker, a nine-year Senae veteran, staked out a position to the left of all of his Republican competitors, and made a blatant appeal for help from Democrats and Independents.

"I don't think I can secure the nomination with just Republicans," he said at one point.

In becoming the fifth declared contender for the GOP nomination, he said his campaign will be a "hardnosed refutation" of Democrats and Republicans who "spit on the Word government and tell a nation used to dreaming and accomplishing the impossible that the futute of America is no more than a good day today."

"I want the nation up, out and looking for trouble -- not running away from it," he added later.

Weicker, who toyed with leaving the party in 1975, displayed his quixotic style best when questioned about fellow Republicans.

Asked for comment about other GOP presidential hopefuls, he said, "I have no intention of discussing anything of interest about other Republican candidates. There's nothing of interest there."

Asked specifically about former Texas governor John Connally, a former Democrat, Weicker said Connally's candidacy for the GOP nomination "shows the bankruptcy of our party."

Weicker enters a Republican field -- likely to mushroom to 10 or more candidates -- far down in the public opinion polls and in the midst of a running feud with the Connecticut GOP chairman.

The son of a wealthy pharmaceutical manufacturer, he has little organization or name recognition outside his New England home area. "I concede the big bucks, the endorsements and the delegates to my opponents," he said.

His campaign is based on the theory that his provocative style and liberal leaning on social policy will attract Democrats and independents into the early New England primaries. It is the same formula that he used to win nine straight elections in heavily Democratic Connecticut, frequently with the opposition of party regulars.

Weicker is best known for his role on the Senate Watergate Committee during its investigation of the Nixon White House. He was the most junior and outspoken member of the committee. His highly moralistic style was alternately described as "very gusty" or "not very smart" or both. Weicker, one columnist wrote, "nearly succeeded... in turning indignation into elpquence during to hearings."

Weicker was born in Paris and raised, along with two brothers and a sister, in comfortable surroundings on Park Avenue in New York City and in Greenwich, Conn. His father was an executive in E. R. Squibb & Sons, a family-owned pharmaceutical house. He is a graduate of Yale, where he was a member of the Political Union, a debating society that included columnist William F. Buckley Jr. as another member, and the University of Virginia law school.

Before winning a tight, three-way race for the Senate in 1970, Weicker had served one term in the House, three terms in the Connecticut state legislature and was twice elected first selectman (mayor) of Greenwich.

He has three children by his first marriage and one by his second marriage.

His announcement was made in a crowded courtroom in the Old State House, which housed the Connecticut state government from 1796 to 1879. The announcement was interrupted by a small group of civil rights activists who accused Weicker of not having enough blacks on his Senate payroll. He has four.

Weicker intends to make his first campaign swing late next week, with visits to Florida and New Hampshire. Today he said he has no intention of altering his style or views as candidate. "If I've got to change, or become a political whore, the hell with it."