Last Thursday, as his weekly press conference came to a close, Maryland Acting Governor Blair Lee III asked the reporters to stay around and listen to an announcement from the Maryland Democratic Party. Some of the party's officials had come down to Annapolis to talk about a new way to select Maryland delegates for the party's national miniconference, a method that could open up the party to minorities and women.

All the reporters heard Lee but many packed up their gear to leave. Radio reporters and television crew members walked up to the podium as Lee was speaking and began unfastening their microphones. Cameramen unplugged the television lights. Reporters rushed out the door to ask politicians for comment on other topics or left for the basement press room.

Well, Less said, maybe only the political reporters wanted to hear about the changes.

A few did. They waited for State Sen. Roy N. Staten, chairman of the state's Democratic Party, for Del. Charles S. Krysiak, from East Baltimore, and for Anne Baker, a National Committeewoman.

"It has been mandated that we open up this party to everyone in the state," Staten began. (Staten is one of these old-style politicians who has been accused at various times of running the party as if it were a private club.)

"I take this very seriously . . . We've got Anne Baker here to head up our affirmative action program," Staten continued. He then introduced Krysiak, Baker and Lee.

The new method was explained. The miniconvention was explained. Lee said he wanted to "make very certain that the word is spread all around the state. Everyone can become a delegate . . . Minorities and women, we have to get them into the act."

The plan was simple. It has been used in other states. On June 17, in each congressional district in the state, a caucus will be held. Every registered Democrat is invited. One man and one woman will be selected, by a mass vote, to represent the district at National Democratic Convention in Memphis this December. There, the delegates will draw up party rules for the 1980 presidential nomination.

"Could the caucuses be stacked?" asked one Baltimore reporter. That wasn't what the party had in mind, answered Baker.

For the doubters, a seven-page pamphlet with four addenda was passed out.

"We're reaching out and encouraging everyone to run," said Lee.

The leaders, though, didn't say whether they thought most Democrats were interested in writing up rules to set up the expensive and confusing machinery to nominate a president.

For the 1974 mini-convention, delegates were selected by voters during the September primary. Besides voting for congressional representatives, state senators and county executives, voters who were patient enough to follow the ballot to the end got to vote for delegates to the party's conventions.

Party leaders decided the caucus method was more democratic. Flyers and advertisements will go out to Democrats around the state asking all to attend. In the 5th District (largely Prince George's County), the caucus will be held at Prince George's Community College, Largo. The 8th District (most of Montgomery County) will hold its caucus at the Montgomery County Educational Services Center, Rockville. The 4th District (southern Prince George's and Anne Arundel Counties) will caucus at Room 100, State Senate Office Building, Annapolis.

Once these reforms would have been a great news item. Once it was an issue very much of the moment.

The elaborate caucuses and the miniconvention are the direct descendants of the urgent years of the late '60s and early '70s. Minorities, women, all who felt left out of the system and wanted in, made demands then for an open door to the party. In 1972, when Sen. George McGovern was the party's nominee for President , their demands were granted.

Part of McGovern's platform included a section mandating a new open system for selecting delegates for all conventions. From then on everyone would have a say in the policies and rhetoric issuing from party headquarters. The system was set in place, revised, and now has rested, finally, on the caucus.

It is not evident, yet, that these changes have made a great deal of difference in Maryland; They aren't even talked about anymoe. Some will measure the effectiveness of the caucus system by the simply expedient bodycount method: by the number of people who show up for the caucus.

But if the Democrats who attend the caucus have a good time, meet a few of their officials and feel just that closer to their party, then a success of sorts will be achieved.