To his right stood Maryland's leading Democratic politician. To his left stretched a line of hundreds of Marylanders waiting to shake his hand.

In the middle of it all stood a beaming Gov. Harry Hughes, a political unknown only four years ago, wrapped tonight in the regalia of incumbency at the $100-a-ticket kickoff of his reelection campaign.

Asked how he felt in comparison to his dark horse days of 1978, Hughes answered between handshakes: "Not as lonely."

The Hughes who greeted guests at Baltimore's elegant convention center tonight bore little resemblance to the candidate who was tagged "a lost ball in high grass" only weeks before his surprise 1978 victory. And the crowd of 2,400 prominent businessmen, politicians and civic leaders contrasted starkly with the 400 who turned out at Hughes' major Baltimore effort of 1978--a Hilton Hotel reception that Hughes had hoped would draw 1,000.

"It's a remarkable turnout considering the weather," Baltimore Mayor William Donald Schaefer said as snow and sleet fell outside. "It shows real enthusiasm for the governor." Anne Arundel County Executive Robert A. Pascal, Hughes' most likely Republican opponent, drew 1,700 people to a fund-raiser in the same ballroom two months ago.

Tonight while a Dixieland band played "Happy Days Are Here Again" and Hughes basked in the spotlight, there were still indications that his support is not as solid as it appears. Mayor Schaefer, a persistent Hughes critic whose support is considered invaluable, was quick to say that his presence did not constitute an endorsement of the governor. In addition, supporters of Baltimore Sen. Harry McGuirk, who has floated plans to challenge Hughes, turned out tonight, not as a show of support for Hughes but "out of respect for the governor. You gotta respect the governor," as one of the McGuirk supporters put it. And one prominent Democrat said the campaign staff had passed out free tickets in the last several days to ensure a large turnout.

Tonight's turnout, while not surprising for a Democratic incumbent with no serious primary opposition, came as a relief to Hughes' campaign committee, whose members have spent three frenzied weeks mailing 15,000 fund-raising letters, hosting breakfasts in Baltimore and dinners in the governor's mansion in Annapolis, peddling tickets to businessmen, civic clubs and politicians - all in hopes of producing a show of strength for tonight's "Tribute to Gov. Hughes."

The ticket sales--estimated at 2,800 for a gross of $280,000--were aided, according to the campaign staff, by the normally reserved governor's election-year efforts to assert himself as a leader after three years of taking a hands-off approach to many issues, and by the results of a poll - carefully timed for release during the week that tickets went on sale - showing Hughes as the clear favorite against Republican Pascal in the 1982 general election.

"Funny how all those things just happened to come at once," a smiling Joseph M. Coale III, manager of Hughes' bustling campaign headquarters, said of the release of the poll, of the 55-year-old governor's intensifying and well-publicized attacks on President Reagan and of his more visible role in this year's General Assembly session.

Tonight's event was filled with contrasts to four years ago, when candidate Hughes was dismissed by some as "Harry Who?" before he rode to a surprise primary victory on a backlash against Maryland's history of political scandals. Back then, Hughes had trouble filling small living rooms for tea parties thrown by supporters around the state. Coale still winces when he recalls the Baltimore Hilton fiasco - "the bomb," he calls it. "I went over there an hour in advance and I just started closing off sections because I knew we'd never fill the place up," Coale said. Tonight's crowd included former Acting Gov. Blair Lee III, the man Hughes defeated to win the 1978 Democratic nomination, as well as U.S. Sen. Paul Sarbanes, Baltimore Congresswoman Barbara Mikulski, Attorney General Stephen H. Sachs, House Speaker Benjamin L. Cardin and dozens of legislators, including some who opposed Hughes in the past and some who say they still do.

The theme of tonight's fund-raiser was "Maryland on the Move." The slogan, intended to embody Hughes' major campaign platforms of economic development, integrity in government and fiscal responsibility, is said to be the brainchild of media consultant Robert Goodman, Hughes' friend and neighbor who advised George Bush's 1980 presidential campaign and who is scripting Hughes' television ads and brochures.

Goodman, who volunteered his services to Hughes in 1978, is on the payroll this year at a handsome, but undisclosed, salary, according to campaign staffers -- another sign of the strength borne of incumbency.

And the cochairmen of tonight's event were three of Maryland's most prominent business and professional leaders -- former U.S. attorney general Benjamin R. Civiletti; Henry A. Rosenberg Jr, chairman of Crown Central Petroleum Corp., and James W. Rouse, developer of Baltimore's Harborplace and the new town of Columbia.

But tonight's respectable head count was only the first of several hurdles Hughes must clear to raise an estimated $1 million for a campaign that is expected to rely heavily on television advertisements. The ads, designed to capitalize on his Hollywood-handsome image, will feature Hughes on official visits to China and France, and on visits to the Maryland hinterlands..

The traditional role of Democratic political clubs is expected to be relatively minor in Hughes' media-oriented campaign - a repeat of the strategy that produced the governor's 1978 victory, when he ran as the candidate of "the people," rather than of "the politicians."

That strategy, a reflection of Hughes' apolitical style as governor, has alienated certain Democratic Party activists, who complain they have been denied customary access to the governor and who threaten to bolt to the ranks of the Republican Pascal. But otherparty regulars are beginning to move closer to Hughes.

"The coolness is still there, but there's nobody else," said a leading Democrat. "I think part of the problem is some people expected Harry to be Superman, but he's not. He's Clark Kent."

Hughes' apolitical and low-key style apparently has inhibited ticket sales in usually reliable quarters - lobbyists, for example, who would be expected to join the incumbent's bandwagon in hopes of currying favor. Several lobbyists who received packages of 10, 20 and 30 tickets from the campaign committee sold few or none.

"Harry makes such a big deal out of not playing the game, no tit for tat," said one lobbyist. "Why should I sell tickets for him when it won't get me a bag of beans? I'd rather be ignored for free than for $1,000."

Hughes' campaign staff is trying to turn his moderate style to its advantage, counting on polls that show Marylanders are tired of flashy politicians such as former governor Marvin Mandel. One fund-raising letter said: "Harry Hughes is not charismatic, not flamboyant, but he is a solid, competent man of high integrity and a depth of knowledge of the state of Maryland and its political systems."

Tonight the normally unflamboyant Hughes was so enthusiastic as a result of the turnout that at one point he took a trumpet from one of the Dixieland bandsmen and played a solo version of "Happy Days Are Here Again" as the audience cheered. Campaign cochairman Rosenberg took the microphone and announced proudly: "We finally got the governor to blow his own horn, and you'll be hearing him do it again and again in the next few months."