House Minority Leader Bob Michel was in an unusually expansive mood when he met with reporters for breakfast last week. For 25 minutes after the formal session had been adjourned and the remains of the scrambled eggs had been cleared away, the Peoria Republican sat around schmoozing about his job, the Congress and the Reagan administration.

He said so much that we had a surplus of copy. One of the items that didn't make the papers was his disclosure that he has urged President Reagan to deliver a television address pretty soon on the defense needs of the country.

Reagan needs to spell out his strategy and the way the weapons systems he is recommending fit into that overall design, Michel said. "Not just in terms of a Russian threat," he added, but in enough specifics that the unemployed workers in Peoria can understand why the president thinks we have to spend these extraordinary sums for new arms.

Otherwise, he implied, Reagan can expect to see Congress slice the defense buildup to save some of the budget-threatened domestic programs.

Some of us at the table thought back to Reagan's evident nervousness about explaining arms policy last fall, when he quickly lateraled to Defense Secretary Cap Weinberger the task of answering White House reporters' questions about the rationale for the MX missile and B1 bomber decisions. We wondered about Michel's assumption that Reagan could make everything make sense.

But if a president has a reputation as the Great Communicator, then it is not surprising that his supporters want him to exercise those talents on behalf of embattled projects.

There is more to it than that, however. What his well-wishers see is that the public is beginning to lose its sense of where Reagan is leading the country--and why. The vision and purpose he communicated so well in 1981 have been blurred by the consternation over his budget deficits and by a series of ill-coordinated statements and actions by administration officials in vital domestic and international fields.

Reaganism has lost its focus, and the president has to redefine it.

Press conferences don't help. Reagan's imprecision in answering questions adds to the misgivings. So why not do what he does well: give speeches to put the main goals of his administration back in focus?

Exactly that suggestion was made in print last week by one of the president's leading academic cheerleaders, Harvard political scientist James Q. Wilson.

Writing in The American Spectator, Wilson said Reagan has erred in putting so much emphasis on cutting the size of government. "The size of government is important in some ways," he concedes, but what really matters to most people "is that government, whatever its size, follow right principles."

Wilson says that Reagan ought to address in "major and sustained presidential remarks," at least four topics.

The first is defense, including the uses of military power and the obligations of military service. The second is the question of income maintenance: defining the "safety net" and setting realistic criteria for including and excluding certain programs and beneficiaries.

The third is the environment: what resources need to be developed and which are to be preserved, and how that distinction will be made. And the fourth is the issue of race relations: how equality of opportunity will be protected without the tools Reagan has rejected, such as busing and quotas.

"At present," Wilson says, quite correctly, "each of these four issues is being managed by lesser officials, on the basis of imperfectly understood criteria, and in ways that lead the press and much of the public to see the matters in narrow partisan terms."

Wilson says--again correctly, I think --that these questions are inherently too important for the president to delegate. He himself--and not his appointees and subordinates--needs to define the terms of public debate.

Implicitly, it seems to me, both he and Michel are urging Reagan to involve himself more fully, not just in articulating policy in these areas, but in thinking through that policy within the administration.

They are asking him to be presidential, in the basic sense of that word. And coming from them, it is advice he can ill afford to ignore.