They are also running, trying hard not to become also-rans.

Two Democrats are opposing formidable incumbent U.S. Sen. Paul S. Sarbanes in the primary on Tuesday, and nine Republicans are vying for a position on the November general election ballot.

It is an eclectic field that includes a communications consultant, a "cultural engineer," a wine salesman, a socialist and a candidate who last ran for the Senate in another state 14 years ago.

None seems discouraged by the conventional wisdom that the chances appear slim, at best, of defeating Sarbanes, who has held the seat since 1977.

But then, few of them are conventional candidates.

Except perhaps for the man they call "the millionaire." That's how his fellow Republican opponents refer to Thomas L. Blair, a Montgomery County businessman running the best-funded GOP primary campaign for U.S. senator.

Blair, 44, is the Republican the others gang up on, a lightning rod who in his first political race is spending $164,000 of his own money, mostly for radio spots and newspaper ads intended to give him name recognition.

"My approach in the primary is to offend as few people as possible, to use the time to develop name recognition," Blair said in his well-appointed campaign headquarters on Montrose Road in Rockville.

The name recognition, he hopes, will translate into a margin of primary victory. After that, he promises to turn his bland primary persona into the colorful and charismatic character of conviction he says he really is.

To a man, however, his Republican opponents contend that a Blair primary victory would ensure the GOP's defeat in November. They say he doesn't stand for anything, that he's missed too many candidate forums and, worst of all, they say that he hasn't voted in an election since 1980 -- he says 1982 -- and reregistered only three days before he filed for the Republican nomination.

"It's either going to be me or Tom Blair. That's my prediction, for what it's worth," said Patrick L. McDonough of Baltimore, a former Democratic delegate to the Maryland General Assembly who recently turned Republican.

But if Blair wins, he warned, "he becomes a clay pigeon on March 9," the day after the primaries.

McDonough, 44, touts his endorsement by the weekly Gaithersburg Gazette. Blair trumpets, softly, the Baltimore Sun's muted backing of him, but he winces at the written words: "He is a millionaire who says he is willing to spend money to get his name and ideas before the state's voters."

Blair replies that he is a self-made man who parlayed a $2,500 loan into a $40 million health care software business with 400 employees.

Which brings a charge from candidate James G. Bennett, 54, a Republican Party activist and an investment counselor from Silver Spring, "He just doesn't come across as a serious candidate, except in his bankbook."

Not all the candidates concede to Blair the name recognition factor, either. In an Eastern Shore poll, candidate E. Robert Zarwell noted, he came in first, with 32 percent, while "the millionaire took 17 percent."

Zarwell, 46, a Severna Park communications consultant, may owe his name recognition at least in part to a gimmick he designed. To every campaign event he wears a flashing plastic badge. "I can go into a room with 200 people, and in 45 minutes people know me," he said.

Whatever the virtues of Zarwell's pin, Blair's media message is hard to miss. A recent caller to a Christian book store in Rockville, where candidate John C. Webb Jr. works, was put on hold, only to hear over the telephone a radio advertisment for Tom Blair. "Oh, you did?" said Webb, 60, who describes himself as a cultural engineer with a Harvard degree.

"I guess he's spending the money," said Webb, a perennial candidate who has raised and spent $700 but does not discount his own chances. "Let's say lightning can strike," he said.

"Monied arrogance" is how candidate Herb Rosenberg, 66, characterizes Blair, whom he also calls "the pick of the litter." Rosenberg, of Silver Spring, a wine sales representative, is hoping his appeal to fellow American Legionnaires will help him win the Republican nomination.

Also running are Horace S. Rich, 68, a retired Army colonel who lives in Baltimore County; Albert Ceccone, 42, a real estate investor from Chevy Chase who said he expects to carry Prince George's and Montgomery counties; and Monroe Cornish, 53, a Baltimorean who filed as an indigent and was therefore exempted from the $290 filing fee.

The Democrats challenging Sarbanes in his own party are A. Robert Kaufman, 56, of Baltimore, who describes himself as a socialist and political activist, and B. Emerson Sweatt, 44, of Charles County, who finished in last place in the 1974 Republican primary for the North Carolina Senate seat then held by Sam Irvin.

Sweatt claims to have been the only Senate candidate in Maryland in 1982 to predict an epidemic of heroin and cocaine.