House Democrats are frustrated because, after more than a month of effort, they have not been able to pass their nuclear freeze resolution. They thought it would be easy: last year they lost by only two votes, and only after the president arm- twisted several members, and in the election they gained 26 seats. Simple arithmetic suggested the freeze would pass easily, and that dubious members would sign on to a cause that seemed as popular as Mom's apple pie and, at the same time, was not really binding anyway.

But that's not what happened. Republicans and some hawkish Democrats have peppered the freeze advocates with questions about how their resolution would operate in practice, and the managers of the freeze resolution have not always had ready or consistent answers. Does the freeze allow modernization of weapons? Would it be undercut by calling for reduction of certain weapons systems?

Freeze advocates have been squirming. They nudge their opponents in the side and say their resolution is only symbolic. It takes effect only if the Russians agree to freeze too, they say under their breath, and since that's not going to happen anyway, why don't you just let it pass?

The freeze resolution is the kind of tactic that a minority employs to attract attention and gain support. But the Democrats now are a working majority, and the Republicans are forcing them to act like one. The 26 seats the Democrats won last November gave them this working majority in the House and the responsibility that goes with it. In 1982 they could slough off objections to the freeze by saying that they were the administration's responsibility. Now they can't: the Democrats are responsible for the ongoing conduct of government too.

They are learning again the old lesson that responsibility carries burdens: what sounds good on the campaign trail may not work so well or so easily in the messiness of the real world. But in their frustration at their inability to slip this resolution through painlessly, they should remember that the responsibility of being a majority also submits a party to a discipline that, in the long run, can be beneficial.

The Democrats, in the process of defending their freeze resolution against plausible Republican amendments, have held their ranks well and developed impressive party discipline. In the process, natural leaders have emerged: some senior members who were, theoretically, leading the Democrats have in effect given way to younger members such as Les Aspin, Les AuCoin, Norman Dicks and Stephen Solarz, who have a solid command of the facts and the arguments. Seniority no longer confers power in the House; it goes to members with talent and energy.

Young Democratic congressmen, whose first political experience in many cases was protesting the Vietnam War, have found themselves not in the position of adolescents criticizing those who run the government, but of grown-ups responsible for establishing policies that can preserve the peace and defend the nation at the same time.

This is the kind of practice any party needs if it is to govern. And in effect the House Democrats are being called on to govern now. The White House has abdicated; it refuses to present a domestic or defense budget capable of commanding a majority in either house of Congress. Senate Republican leaders are understandably weary and battle-shy after putting together last year's budget and tax bills; the Senate Budget Committee just sent to the floor the House Democrats' budget for want of anything else to do.

The House Democrats are in effect the lead partners in a European-style coalition government; they have the responsibility to come forward with the major policies no one else will produce. They have already done so on the road and gas tax, the Social Security rescue bill, and the budget. Now they are challenged to come up with a plausible defense strategy.

This is not an easy task; perhaps it is impossible. Budget Committee resolutions giving percentage increases or campaign rhetoric about the nuclear freeze will not suffice. The hard part is ahead: can the House cut the administration's defense budget when it has to deal with specific items in the defense appropriations, when members have different views and districts with different interests? Probably not, in which case Defense Secretary Caspar Weinberger's strategy of ignoring the budget resolutions and counting on the defense appropriations bills to provide the money he wants may pay off.

But he may be frustrated if the debate on the nuclear freeze resolution has given the Democrats the discipline and leadership--the habits of thinking and acting like a majority --that they need if they are to act coherently on this issue as they have on others.