CREDIT IT TO austerity, the wicked winter weather or the absence of vigorous leadership, but the 1977 Maryland General Assembly was able to wrap up the session with its mediocre record unblemished by any remarkable accomplishments. That's just about the way Gov. Marvin Mandel had expected things to go, as you recall from his opening address to the lawmakers in January. The governor had set a list of unspectacular goals and, with a little extra effort, the Assembly managed to meet at least some of them.

One such action - one that will affect every Marylander - was enactment of an increase in the sales tax from 4 per cent. This was the first time in eight years that the Assembly had been asked to approve a significant tax increase; and, after much balking and posturing, they reluctantly succumbed to the fiscally inevitable. It wasn't the most progressive way to raise money, but given the legislator's inability to cut the governor's budget, the increase carried.

As we have noted on more than a few occasions in this space, there is far more equitable way to raise additional revenues: by adjusting the state income tax rates. This tax now ranges from 2 to 5 per cent, but the highest bracket includes everyone with a tax-able income of more than $3,000. That leaves a lot of running room for new higher brackets - but not enough lawmakers were in the mood for such a graduation ceremony this year.

On another fiscal front, Gov. Mandel's proposal to limit residential property assesment increase failed. As the session ended without the governor around to exert influence, his goal of relieving the property tax burden went on unmet: Proposals to increase school aid to local goverments and to extend circuit-breaker provisions (trying property taxes to ability to pay) both failed. Also, for the third consecutive year, the legislators failed to make necessary improvements in the campaign-financing law. Without more money, the law can't work.

Undoubtedly, each member of the Assembly will find some accomplishment to cite for constituent consumption. Still, Marylanders may well ask what it takes for their state legislators collectively to come up with the strong leadership necessary to produce a more equitable tax system.