Daniel J. Minnick, a Baltimore County delegate in the General Assembly and member of the House leadership, has an ethical problem this session. The owner of a Dundalk tavern, Minnick is the sponsor of a bill that would prohit 18- to 21-year-olds from buying alcohol unless they buy it and drink in taverns. Minnick acknowledges that his support for the measure represents a financial conflict of interest, and says that he may abstain from voting for it when it reaches the House floor. But then again, he adds, he may just vote for it anyway. "I'll have to see how the bill does in committee before I decide whether to not vote," he says.

Minnick's deliberations indicate what has happened to the General Assembly's efforts to regulate and reform the ethical conduct of its members. For, if Minnick decides he wants to vote, all he needs to do under the state's ethics law is file a sworn "disclaimer" statement declaring that his judgment is not affected by his personal stake.

His case if far from isolated. This year, as always in this part-time legislature, there are tavern owners sponsoring drinking bills, insurance agents promoting eased guidelines for their work, and lawyers and doctors whose bills would increase the business and benefits of their professions. Some of that activity is covered under the ethics rules; most of it is not. In any case, little of it seems to have been impeded or even regulated by the legislature's ethics reforms.

For five years in the 1970s, the General Assembly passed a series of financial disclosure and conflict of interest rules in an attempt to establish an ethics code in the wake of years of political scandals. Finally, in 1979, the legislature enacted a thick new ethics law, written by the legislative leadership, that revised and expanded the work of previous years and that its supporters called "miraculous" and a "milestone first step" in political reform.

Today, only two years after that last major bill passed but long after the enthusiasm for political reform in the legislature has faded, it seems clear that the detractors of the wide-ranging ethics laws were right when they contended, as one of them put it, that the laws "had so many holes in it it would put a Swiss cheese to shame."

Meanwhile, support for even the weak ethics laws that now exist seems to be evaporating rapidly in the legislature. Last week, Prince George's Del. Francis J. Santangelo, cited for "disapproval" by the House for violating financial disclosure laws that predated the 1979 stature, received a thunderous standing ovation when he rose to denounce the proceedings against him.

And already members of the legislature's Joint Ethics Committee, which was given new powers under the 1979 law to investigate conflicts of interest and other misconduct, have become "cautious," in the words of cochairman Sen. Julian L. Lapides (D-Baltimore), for fear that their authority would be stripped if it is fully used. "We have a long wayt to go in regulating ethics," Lapides says. "But if we were too open or aggressive now, you'd see the law being eroded."

The last and most comprehensive ethics law was hastily drafted by several legislative leaders, including House Majority leader Donald B. Robertson, midway through the 1979 session. Most of the new law applied not to legislators, but to non-elected state officials.

Almost as a footnote, Robertson and the other sponsors agreed to take General Assembly rules governing ethical conduct, established several years earlier, and incorporate them into the new law, strengthening them slightly along the way. These provisions basically require a legislator who has a conflict of interest on a bill to abstain from voting on it or file the public disclaimer statement allowing him to vote.

"We knew that wasn't necessarily the answer," Robertson says now, "but we were working under a lot of time pressure and we didn't have time to do much more. It was a poltical decision, really: it would look very strange if we had passed a ethics law that said nothing about the General Assembly".

Robertson and the law's supporters maintained now and then that by enacting the existing rules into law and giving the legislature's own ethics committee power to question disclaimers and initiate investigations of possible conflicts, the legislature has made more or its members conscious of financial conflicts that were frequently ignored up until 1979.

But Lapides and Robertson concede that there are many legislators who, as Robertson carefully words it, "have a lack of understanding or sensitivity to what the ethics law requires of them."

Take Baltimore Del. Frank Conaway, for example. An insurance agent, Conaway is sponsoring two different bills that apparently would directly increase the amount of money he makes. One bill would make it easier for insurance agents like himself, who write policies for the state-run insurance fund, to sell those policies. A large portion of Conaway's business is in that area. Another bill would eliminate the $5,000 bond each insurance agent is required to post with the state and set up a state-run insurance agents guarantee fund instead.

And yet, Conaway not only is sponsoring and voting on these bills, but until recently maintained that there was no need for him even to file the routine "disclaimer" statement. "These bills are not to my best interest," he insisted. "I've never put in a bill to help myself. Anyone who would read my bills would never say I had a conflict."

While Conaway simply chose to ignore the ethics rules -- he finally filed a disclaimer only when pressured by Ethics Committee members -- many other legislators have used the disclaimer provision openly to work and vote on legislation in which they have direct financial stakes.

This session, for example, as the legislature prepares for a major debate on the interest and credit card rates charged by banks, 20 delegates and senators have filed disclaimer statements allowing them to vote on the bank bills, even though they are stockholders, employes or board members of banks.

Then there is the proposal that came before a Senate committee last week to prohibit elected officials from representing or receiving financial benefits from cable television firms. Such firms have hired a number of politicians in the local area to help them win lucrative franchises from local counties and municipalities.

One of the opponents who testified against the bill was Montgomery Sen. Laurnce Levitan, who has disclosed his interest in cable television and therefore felt justified in lobbying against the bill, which, he maintained, represented a "personal attack" against him.

Levitan also is sponsoring a half-dozen bills designed to clear away what he believes are technical problems in mortgage and property settlement law, which represents his chief source of income as an attorny.Likewise, Del. Torrey Brown (D-Baltimore City), has sponsored a wide range of bills that revise various statutes of the medical profession. Brown is assistant dean of the medical school at Johns Hopkins University.

Brown, who has filed no disclaimer with the ethics committee, and Levitan argue that their bills have little or nothing to do with their personal finances, and in fact represent the advantages of a part-time legislature.

"That stuff I've put in nobody else would be able to understand or explain, but it's important," Levitan says. "The legislature would have a hell of a time dealing with farmers' issues if it didn't have any farmers in it. And it would have a hell of a time with interest and mortgage and real estate issues without people who are familiar with that."

While they agree with this argument, the legislative leaders who supported the ethics laws now concede that the disclaimer provision and other rules they enacted have created a situation in which, as House Speaker Benjamin L. Cardin (D-Baltimore City) put it, "there are 188 different subjective standards of ethics."

"The problem with the ethics law is that we don't get to what we really want," said Del. Kay Bienen (D-Prince George's), the Ethics Committee cochairman. "There are members from every legislative body who put in measures from which they are directly going to benefit and there's no way of us knowing."

Cardin and Robertson are planning to have a legislative committee study the ethics laws this summer to try to find ways to clarify and tighten them. But in the present anti-ethics mood of much of the legislature, supporters of tighter laws seem to be hoping now just to hold on to what they have.

"There is never enthusiasm to pass ethics laws, unless you have a special set of circumstances," said Del. Luiz Simmons (R-Montgomery). "In the middle of late '70s the opportunity was there. That was the time to bite the bullet and get a reasonable code. But the leverage was frittered away. Now it's clear that the people who were pushing those laws became their own worst enemies."