Midnight was approaching and Del. Luiz Simmons (R-Montgomery) was ensconced in an armchair in the House of Delegates lounge, looking at the swirling activity around him with a tilted half-smile on his face.

"I did not think I would feel nostalgic about this chamber but I do," he said. "There have been a lot of frustrations here the last four years. But there are a lot of things I will miss not being here. Maybe if I was 10 years older my expectations might be dimmer. But . . . . "

Simmons' unfinished sentence summed up the mixed emotions of many of the delegates at Monday night's adjournment of the Maryland General Assembly.

Del. Raymond E. Beck (R-Carroll), one of 19 delegates expected to seek another office, said in an emotional closing speech, "some of us will not be back here by choice and some of us will not be back by popular demand."

Simmons is one of those who will not be back by choice. Barring a last-minute change of mind, he will announce his candidacy for Montgomery County executive sometime in the next few weeks.

As the session closed, political ambitions that have been lurking beneath the surface burst forth. Many delegates are giving up safe seats to seek higher office and many, because of redistricting, will be hard pressed to retain their current offices.

Two Democratic Anne Arundel County legislators, Sen. H. Erle Schafer and Del. O. James Lighthizer, will give up their seats to run for that county's executive spot now held by Robert Pascal, who is seeking the Republican nomination for governor.

"Why give up a safe seat to get into a race like this one?" Lighthizer asked rhetorically. "Opportunity. I could live with the idea of spending the rest of my life in the House of Delegates because I think you can accomplish a lot. But you are one of 141. People can hide in here."

As the legislators head back to their districts and their campaigns, hiding will be difficult. Because of redistricting, many will be dealing with new constituencies. In several instances, because of redistricting, incumbents will face incumbents. One of the more interesting cases of tribal warfare during the session was the ongoing battle among the six delegates from Baltimore's 46th and 47th districts. Because of redistricting, the six--Anthony M. DiPietro Jr., Patrick L. McDonough, Louis V. Cavallaro, Raymond A. Dypski, American Joe Miedusiewski and James R. Dietrich--will be running for three seats. Throughout the session, they voted as a bloc, afraid to be cast adrift on any issue.

More than a dozen delegates will be trying to move to the Senate, and several will be trying to do what reportedly only three have accomplished in 60 years--unseat an incumbent senator. One who likely will attempt this feat, Del. Stewart Bainum Jr. (D-Montgomery), watched in agony in the final days as several pieces of legislation he had introduced died in the Senate.

"Vic Crawford did it to me, I'm sure of it," Bainum said in the early hours of Tuesday morning, a reference to Sen. Victor L. Crawford, his anticipated opponent.

Such seeming paranoia was not limited to those looking to move up. Del. Mary Boergers (D-Montgomery), who earned a reputation among fellow delegates as one of the brighter new members in this, her first year in Annapolis, was upset by a story in a local newspaper that called her "bubbly."

"Do you think people are going to want to vote for somebody who's bubbly?" she asked, not the slightest trace of bubble in her voice.

"I think the kind of session we had will help the incumbents," said Speaker Benjamin L. Cardin. But what Cardin terms success--approval of higher interest rates and an increase in the gasoline tax, for example--does not necessarily include the kind of issues incumbents want to base a campaign around.

"In 1978, we passed a $10 million tax cut," said Del. Gerard F. Devlin (D-Prince George's). "That's the kind of thing you go out on the hustings and campaign with, not the fact that you passed a gas tax. A lot of us who voted what I would call responsibly have left ourselves open to demagoguery."

Perhaps Sen. Harry J. McGuirk (D-Baltimore), who is taking the largest political risk of anyone, giving up a powerful committee chairmanship to challenge an incumbent governor, summed up the 90 days best in a political sense:

"The governor can say he had a good session but a lot of that was because the legislature helped him have a good session. We helped Harry Hughes. But more important, we helped the people in the state of Maryland by helping Harry Hughes."

Someone pointed out to McGuirk that his summation sounded like a political speech. McGuirk smiled innocently.

"Now why," he asked, "would you say a thing like that?"