In a few months, Maryland Gov. Harry Hughes will try for the second time in his career to do what he A failed at three years ago: to pick a suitable Democratic running mate for his gubernatorial campaign.

So far, there is only one consensus. The choice this year will not be the current lieutenant governor, Samuel W. Bogley III, who was a Prince George's County Council member when Hughes picked him out of desperation three days before the filing deadline in 1978.

That hasty union was put under strain almost immediately, causing public embarrassment when the two differed sharply on the issue of abortion. It is a marriage Hughes now hopes to annul, and not to repeat when he ties the political knot again this year.

Although Hughes insists that his decision on a running mate will not be made until after the legislative session ends in mid-April, his political advisers have gone to work early. They say their list of candidates is long--"they're coming to us this time," one aide says--a stark contrast to the begging and pleading that was required of the then-unknown Hughes his last time around. In 1982 he is courting prospective matches with promising polls that show him, the Democratic incumbent, a clear favorite against Republican challenger Robert A. Pascal, the popular Anne Arundel County executive. And he is looking for someone who can bolster his ticket in areas that have shifted politically because of demographic changes and legislative reapportionment.

But the chore is not as easy as the Hughes campaign makes it seem. The unhappy tenure of Sam Bogley has made some potential candidates skeptical about going into a partnership with Hughes. More significantly, the governor has made political enemies in key areas, notably in the personages of several leading Baltimore politicians--including Democratic Mayor William Donald Schaefer and Senate Chairman Harry J. McGuirk, the latter of whom is expected to announce his own candidacy for governor next week. Since Baltimore political support is vital to state-wide Democratic candidates, Hughes now is in the position of trying to offset opposition from McGuirk and Schaefer by finding a Baltimorean who will run with him, which will be no small task.

Conventional wisdom here says there are two logical choices: House Speaker Benjamin L. Cardin, the 38-year-old Democrat from the city whose respect among legislators and whose mastery of the legislative process cannot be equaled, and Baltimore County Executive Donald Hutchinson, a Democrat whose presence as a running mate would outweigh potential losses in Baltimore by giving Hughes much-needed votes in a county that now has the voting strength of the state's biggest city.

Either choice would be a stroke of genius, political observers here say, but apparently neither choice is meant to be. The scuttlebutt among legislators is that Hutchinson has been offered the spot twice, and has turned it down both times.

Cardin, in turn, appears to be weighing his future very carefully. A longtime critic of Hughes, Cardin reportedly has confided to close associates that he believes Hughes is vulnerable and that running with him would be too great a risk for a young politician with a bright future.

Cardin makes no attempt to conceal his own interest in running for governor in 1986, and speaks openly about his possible strategies. He has taken a poll, which found that he virtually is unknown outside his home base of Baltimore. Now he faces the question of whether to run with Hughes (presuming he is invited to) in order to use the lieutenant governor's office to garner more attention, or to hire a media consultant in 1983 to help spread his name and his message to the hinterlands--in this case Montgomery and Prince George's counties, particularly.

"I don't want my political future to be tied to someone else's," is about all that Cardin will say, adding that he would prefer to pay for a media consultant than to use a political office for campaign work.

With Hutchinson and Cardin looking less and less likely as Hughes running mates, speculation turned briefly a few weeks ago to politicians from Montgomery County, where Hughes already is politically strong. County Executive Charles W. Gilchrist's name was tossed around, but he reportedly no longer is under consideration. Eyes have turned to Del. Nancy Kopp, an expert on the state budget who is chairman of a House appropriations subcommittee. She has been approached by Hughes, according to sources, but not formally asked.

Hughes' aides refuse to confirm any names on the list of candidates, and insist that they are not "waiting for anyone Hutchinson, Cardin to accept an offer."

Sources in the Hughes campaign say the governor's advisers are pushing him take a politician from Baltimore, perhaps even from the ranks of city officials.

EPILOGUE: There was no wild applause when word reached the House and Senate chambers last week that Lt. Gov. Bogley (at last) had taken a parting shot at Gov. Harry Hughes in public. Bogley, in raw language, proclaimed that he had not been treated fairly by the Hughes administration and implied that he would consider switching parties.

Although many legislators here believe that Bogley has been humiliated because of three awkward years as the governor's super-subordinate in the Maryland Statehouse, their reactions to his "gloves-off" attack on Hughes at a Republican fund-raiser were, at best, either mildly disapproving or just plain bored.

Bogley has had neither an active nor an interesting tenure. His position as a do-nothing lieutenant (albeit a charming, humorous and self-effacing one), has not led to greater sympathy for him, as he might have expected, but to renewed calls in the legislature that the number two position be either abolished or upgraded.

To show his (commonly held) view and lack of respect for the office, Sen. Julian L. Lapides (D-Baltimore) recommended to his colleagues on the Senate Budget and Taxation Committee that the governor's proposed raise in the lieutenant's salary be rejected. Lapides also has introduced a measure that would allow voters to decide next fall whether to fund the office at all.

In addition, Senate President James Clark Jr. (D-Columbia) has introduced a bill that would abolish the office of lieutenant governor.