Four months ago, on a snowy winter night, Maryland Gov. Harry Hughes began his drive for reelection with a $100-per-person fundraiser. Tonight, that campaign drive passed the $500,000-mark when Hughes held his first major fund raiser since he officially announced his candidacy and introduced his running mate.

Hughes stood amid a crowd approaching 1,500 at Martin's West catering hall with his wife, Patricia, and lieutenant governor candidate, State Sen. J. Joseph Curran Jr., and Curran's wife, Barbara.

As a band blared in the background and campaign aides handed out spanking new Hughes/Curran bumper stickers, Hughes surveyed the scene with uncharacteristic enthusiasm.

"The turnout is fantastic," he said. "I have a good running mate, we had a good legislative session and I feel even better tonight than four months ago. And I felt very good then."

Later Hughes told the crowd: "You're going to hear that Marylanders know what they have in the governor's mansion , like what they have and are going to vote to keep it." Then, in what has increasingly become a campaign trademark for this usually low-key governor, Hughes picked up a trumpet, turned toward the crowd and played "Everything's Coming Up Roses," causing one aide to comment "he's been practicing."

Hughes' campaign staff has been steadily raising money toward a $1 million goal since last winter, when Hughes held the $100-a-person event in Baltimore's convention center.

The campaign has been soliciting funds by mail and recently the governor began attending a series of private dinners designed to give major political contributors the chance to socialize with Hughes and his wife, Pat, and then contribute between $500 and $1,000 to the campaign. According to campaign aides, each dinner is expected to bring in $15,000 or more.

All of this has put Hughes well ahead of all opponents financially, a situation quite different from 1978 when he ran as the underdog. Then, Hughes nearly dropped out of the Democratic primary because of lack of funds. This time, the Hughes campaign has been able to begin mailings and go on the air with television advertisements weeks before anyone else.

Hughes' main opponent in the Sept. 14 primary, Baltimore State Sen. Harry J. McGuirk, has raised $100,000 so far for his long-shot race. McGuirk says he has gotten pledges of about $250,000 and expects to raise another $100,000 at a fundraiser scheduled for next week. In addition, McGuirk's running mate, Lt. Gov. Samuel Bogley, who ran with Hughes in 1978 but was dumped from the governor's reelection ticket, is expected to raise money for the ticket from his wealthy in-laws.

The only Republican candidate for governor, Anne Arundel County Executive Robert Pascal, has raised $200,000 so far and has a major fundraiser scheduled for next week. Pascal admits he has had some trouble raising money for his race against Hughes, who has the advantage of incumbency and of being a Democrat in a heavily-Democratic state, but he says it is all part of his strategy of not peaking too early.

Despite Pascal's optimism, his money-raising difficulties have delayed the start of television advertisments that are thought to be the only way he can increase his low name recognition. The ads, which were to begin June 1, also may have to be cut from three weeks to one.

Although Hughes is far ahead in the fundraising sweepstakes, a few signs have surfaced in the last weeks that could indicate the governor may have more of a reelection race than most politicians had expected.

Bogley, now a candidate on an opponent's ticket, has promised to vigorously point up the failings of his 1978 running mate. McGuirk has said he will win the support of party regulars disgruntled by Hughes' apolitical style -- although most of them were not behind Hughes in 1978, either. Pascal may have behind-the-scenes help from the popular mayor of voter-rich Baltimore, William Donald Schaefer, a feisty Democrat who has made no secret of his dislike for Hughes.

Hughes jokingly made reference to Schaefer's well known frostiness tonight when, having introduced one of his supporters, former Baltimore Mayor Thomas D'Alesandro Jr., as the "greatest mayor the city ever had," he quickly added: "and the current mayor says that, too. He didn't tell me that, but he said it." The comment from a smiling Hughes produced chuckles throughout the crowd.

"It's a superb turnout and why not; he's a decent guy," said Sen. Julian L. Lapides (D-Baltimore), a past critic of the governor. "Clearly he's considerably out front. I think they McGuirk and Bogley will run a campaign, but I don't see it jelling. Hughes may not be a saint even with Joe Curran on his ticket, but in Maryland politics he's the closest thing there is."

Lapides was one of many politicians who turned out for Hughes tonight; others included Attorney General Stephen H. Sachs and Baltimore County Executive Donald B. Hutchinson. The one notable absentee, although it was hardly a surprise, was Mayor Schaefer, but as one Baltimore County state delegate noted, "He would never come here, this is Baltimore County."