MARYLAND'S MASTER magician has to be Harry Hughes, who also plays the part of governor from time to time. Not only can he perform a stunning political vanishing act right before the eyes of an astonished state legislature, but with a flick of an election-year wand he can instantly change the color of Maryland's financial books from red to long green.

Only months ago, a hand-wringing Mr. Hughes was lamenting the disappearance of a "surplus" in Annapolis, warning of austerity and talking taxes. Now, after taking a political powder during critical deliberations over taxes in the General Assembly, the governor shows up with--presto--a "surplus" again. How remarkable the way Maryland's financial and political forces are intertwined from election to election--and what these ups and downs allow: now the governor can talk not of new taxes, but of raises for state employees.

There's nothing new, of course, about this sort of math; the old "surplus" trick is a mainstay among the games governors play. But when you do this nowadays, the effect is more complicated--the fiscal health of the state matters more than ever to its strapped local governments. Will the state government once again be the great golden egg for all the counties? Or should local governments continue tightening belts and expanding taxes?

Certainly even the best of calculations and projections can and do vary from month to month, what with inflation, recession, slow recovery, consumer moods, higher interest rates and everything that has to do with the price of eggs. But Gov. Hughes and State Comptroller Louis L. Goldstein could do a much better job of explaining what is happening and what the state should be doing besides filling the pay envelopes of state employees while ignoring for the moment losses in federal funds--make that read state services--that are just around the corner.