Maryland Gov. Harry Hughes was following his wife Pat to their box this afternoon about three hours before the start of the Preakness. As Hughes was walking through the door leading to the box, an usher stopped him.

"Do you have a ticket?" he asked.

Hughes stopped for a moment, slightly bewildered, and looked as if he might start searching for a ticket, when another usher stepped in quickly to tell his partner, "He's the governor."

Considering the number of politicians milling about in the shade of the grandstand, the young usher's confusion was understandable. Fifty feet from where Hughes sat was Anne Arundel County Executive Robert A. Pascal, the lone Republican challenger to Hughes.

"Am I going to go over and say hello to Harry?" Pascal replied to a question. "No. Why mess up a nice day for both of us? Anyway, he's not going to vote for me."

The 80,424 who jammed into this sun-drenched track today came for a variety of reasons. The politicians came claiming that fun was their motive. But the chance to shake a few hands--or in the case of state Comptroller Louis Goldstein, a few thousand hands--was irresistable.

"It's a chance to see people and a chance to relax," said Sen. Harry J. McGuirk (D-Baltimore) who is opposing Hughes in the Democratic primary. "But people don't want to know what you're running for or who you are. Out here, they have one question: "Have you got a winner?"

Four years ago, when he was a candidate for governor, former Baltimore County executive Ted Venetoulis spent a good deal of his afternoon working the infield. None of the candidates went that route today.

"It's hard to do that," McGuirk said. "Most of the people down there have been there since yesterday anyway." McGuirk's implication was clear: If there were political points to be scored, they would be scored among the well-dressed crowd in the grandstand.

Hughes, ever the nonpolitician, lingered over lunch in the track's conference room, finally making it to his box just before the sixth race began. "I'm here as governor and as a fan," he said. "I'm not here to do any politicking."

Hughes had one more problem today. With two dollars clutched in his hand he tried to get a last-minute bet down before the sixth race. He arrived an instant too late. Even the power of incumbency couldn't help him at the betting window.

As Hughes relaxed in his box, his press secretary, Lou Panos, was still sitting on the terrace watching the politicians go by. He was discussing the reports that Sen. J. Joseph Curran Jr. (D-Baltimore) is going to be Hughes' running mate. "You know," Panos said with a slight smile. "The governor and Ben Cardin will have a chance to talk this afternoon."

The Hughes people, who do not want to announce a running mate until the end of the month, are trying to keep alive the idea that Cardin may join the ticket. When Cardin was asked about that possibility, he said, "I think I'm going to place a bet."

Twenty boxes down from the governor's entourage, Baltimore Mayor William Donald Schaefer was sitting with his friend Henry Rosenberg, chairman of Crown Central Petroleum and the cochairman of Hughes' finance committee. Rosenberg is one of the few links between the mayor and the governor.

Schaefer was asked if he planned to join Hughes on a tour of the Baltimore Harbor Tuesday, an event that is part of Hughes' formal announcement for reelection.

"Won't be there," Schaefer said pointedly. "I'll be away. Far away."

He wasn't smiling. When the subject of an endorsment for a gubernatorial candidate came up, Schaefer said, "No politics today."

There was plenty of political talk to be found, though. Del. Paul E. Weisengoff (D-Baltimore) had a table staked out by the window on the terrace. Dressed in Pimlico yellow and smoking a cigar, Weisengoff, a McGuirk protege, was enjoying himself. The subject was Curran.

"I thought," Weisengoff said, blowing cigar smoke, "that Harry Hughes wanted to get rid of Lt. Gov. Sam Bogley." Weisengoff was implying that, like Bogley, Curran is a quiet, stay-in-the-background type of person. "The only difference I can see is on the abortion issue."

While Weisengoff was discoursing, McGuirk was insisting that, contrary to rumors, he plans to stay in the race for governor. "I know there are people out there who are looking for someone who is different than Harry Hughes," he said. "There's a lot of undecideds out there. My problem is convincing people I'm a candidate."

McGuirk is planning a $100-a-plate fund-raiser for June 29, a week before the filing deadline. Today he was doing lots of handshaking and advising friends which horse to bet. "I'm betting Aloma's Ruler because my college roommate Nathan Scherr owns him. Anyway," he said with a smile, "I'd rather bet a sentimental favorite than the betting favorite."

McGuirk's horse won the race. Today, anyway.