THIS WEEK the state senators in Annapolis really outdid themselves. As a way of saying boo to a proposed increase in the sales tax, protesting rising property assessments and showing some independence of Gov. Marvin Mandel, many of them decided to vote against the state budget. So many, in fact, that to their surprise the budget was rejected.

Well, that wouldn't do. There's a bit of a requirement that a state budget be approved before the legislators can call it a year in Annapolis. So two days and several gubernatorial exhortations later, enough senators had had second thoughts to reverse the earlier vote. Now, many of the switch-voters in this game are vowing not to support the measure that would make the budget they approved financially possible - namely, Gov. Mandel's proposed increase in the sales tax from 4 per cent to 5 per cent.

That's "fiscal responsibility" for you. To be sure, the sales tax is not a progressive way to raise money, nor itis a popular levy to increase. But the state Senate and the House of Delegates can share the blame for this discomfort. They didn't face the music when they first convened: It would have been far more equitable to increase and restructure the state income tax.

That tax now ranges from 2 to 5 per cent - but the highest bracket includes everyone with a taxable income of more than $3,000. Del. Benjamin Cardin (D-Baltimore) and a joint committee on tax reform suggested some time ago that there should be higher personal exemptions and more steeply graduated rates. In addition to shifting more of the tax weight to higher income residents, the proposals would have generated more revenue than would the sales tax increase. Moreover, local governments would stand to gain, for their income taxes are pegged to the state's. Such a move might even have enabled the state and local officials to relieve some of the property tax pressure that homeowners are feeling.

But few around Annapolis felt this way was the year to make a bold move a behalf of a more fairly graduated income tax. There's never an ideal year to overhaul taxes. But as more and more Marylanders realize that their financial stresses are aggravated by their lawmakers' refusal to enact a fairer income tax, perhaps enough legislators will find the time for more than tinkering.