VETERAN campaign-watchers in Maryland shouldn't be too taken aback by the latest reports that suspended Gov. Marvin Mandel is still keeping a hand in the campaigning for governor. After all, politics has been his life - and the fact that he is appealing a criminal conviction does not disqualify him as an expert on the ins and outs of sucessful campaigning in Maryland. True, the dispatches outlining his participation in this campaign may have you wondering if anything has really changed - or whether machines and corruption remain the tools of the trade. But there are reassuring signs that those days may be over - that business-as-usual is out - even while Marvin mandel himself remains an active and respected political consultant.

It is encouraging, for example, that no candidate is actually eager to be fully identified with Mr. Mandel: Nobody's claiming that such an alliance would carry much weight with voters these days. It's also heartening that there is no single, machine-made Democratic designee to inherit the throne. Acting Gov. Blair Lee III, who was Mr. Mandel's running mate last time, doesn't enjoy quite that status, even if it's still considered a political plus.

True, at the persoanl invitation of several hosts, Mr. Mandel has made frequent appeances at political fundraisers. But he is not the kingmaker of old. Rather, we find him serving more as technical adviser and broker for various political candidates. He played an early role in negotiations that ultimately paire Mr. Lee and Steny H. Hoyer. And a close associate of Mr. Hoyer, Peter F. O'Malley, claims that Mr. Mandel made a call in late May to see whether Mr. Hoyer was considering running on a ticket headed by Francis (Bill) Burch.Moreover, that call was "on behalf of Burch," says Mr. O'Malley, though Mr. Burch says he doesn't remember asking Mr. Mandel to make such a call, and Mr. Mandel claims he doesn't remember placing it.

Be that as it may, it's Mr. Lee with Mr. Hoyer now, and the two of them can work out how they'll handle the Mandel connection. Meanwhile, the field is full of other Democratic candidates for governor. In addition to Messrs. Lee and Burch, the list includes Harry R. Hughes, Walter Orlinsky and Theodore G. Venetoulis. Republicans, too, have a choice among four candidates: J. Glenn Beall, Carlton G. Beall, Louise Gore and Ross Z. Pierpont.

All these changes have mant that, so far, we're not hearing so much about some of the more familiar elements of old-time Maryland politics: the clubs, "walk-around money" and fat-cat contributors. One keen Democratic veteran, Richard Schifter of Montgomery County, has suggested that "the people will vote along social group lines, not political clubs. If you make a good presentation to the local bar association, then the lawyers will talk among themselves. It's the same with teachers, holy-name societies, active Jewish groups. That's how the word is passed around now." While that may sound like what happens in many other states, it's something new in Maryland. It's about time.