President Carter wooed 200 Maryland political and business leaders at the White House yesterday, but the only person who came to a solid conclusion about the future appeared to be State Sen. Frederick C. Malkus Jr.

Malkus, who has represented the Eastern Shore in the state legislature for 32 years, drove his car to the New Carrollton Metro station and rode the train downtown for the day-long briefing.

As he left the White House, Malkus was asked what impressed him most about the day.

"The subway," he thundered. "I rode it for the first time, and I wasn't impressed, I didn't like it. And I'm not going to vote money for it again."

The White House billed the meeting as a nonpolitical "Maryland state constituents briefing," but State Sen. Harry J. (Soft Shoes) McGurick of Baltimore noted that "the lunch was paid for by the Democratic National Committee."

Former Acting Gov. Blair Lee III, looking relaxed and joking with aides about "trying to get a job," said there was "an element of missionary zeal" about the meetings with the president, vice president Walter Mondale and senior White House aides. "But they were not crass about it," Lee said. 'They didn't lay it on too hard."

Lee added he has "every intention of supporting" Carter's re-election bid.

But Lee's successor, Gov. Harry E. Hughes, was coy when asked who he will support.

"I'll make that decision on my timing," he said.

No one seemed to know who put together the guest list, which included about 45 members of the legislature, nine labor leaders, five clergymen, five journalists, a dozen real estate brokers and developers, a couple dozen city and county politicians, including Mayor William Donald Schaefer of Baltimore and Montgomery County Executive Charles Gilchrist, and assorted leaders of business and industry.

One person who wasn't impressed was State Sen. Clarence Mitchell III of Baltimore, who complained that there was too much talk about the Middle East and "not enough about blacks who are going to be cold this winter." He also observed there was "not one black" among the staffers who talked to them.

But many of the Marylanders interviewed on the north portico of the mansion appeared to agree with the assessment of State Sen. Sidney Kramer of Montgomery County, who said he was impressed by the president's 15-minute talk in the East Room.