Panelists for the American Enterprise Institute will close out a week of speeches and seminars today after touching on such topics as "The Domestic Budget Agenda for the Next Four Years" and "Politics and Policy in the 99th Congress." Their audience may be in the conference rooms of the Mayflower Hotel, but their targets are on Capitol Hill and at the White House.

However, the AEI faces some stiff competition for the policy makers' attention: the U.S. Catholic bishops, the Heritage Foundation, the Cato Institute and the liberal Center for National Policy all have put forward or are preparing their own agendas for 1985 and beyond.

In Washington, it can be said that the seasons -- and events -- revolve around quadrennial presidential elections, the biennial return of lawmakers to Capitol Hill and the annual submission of the president's budget. Thus, it was not at all coincidental that:

* The Catholic bishops waited until after the presidential election last month to release a controversial pastoral letter deploring poverty and advocating some traditional liberal solutions for government job-creation and a general redistribution of wealth.

* The Heritage Foundation, whose 1980 "Mandate for Leadership" has been described as the inspiration for many Reagan administration initiatives, followed up this year with a "Mandate for Leadership II: Continuing the Conservative Revolution." The document, parts of which have already been released to the press, will be officially made public today.

* Late last month, the Center for National Policy, often described as the Democratic Party's unofficial think tank, jumped into the debate over taxes and budget deficits with its own volume of policy options. Directed by former Council of Economic Advisers chairman Walter W. Heller, the CNP report ended up praising some features of the Treasury Department's just-released tax-revision plan.

* The New York-based Hudson Institute has scheduled a Dec. 11 meeting to decide what, if any, policy options it will recommend in coming months.

Timing policy papers and reports to the rhythm of the national debate is nothing new, but the success of the Heritage Foundation's efforts four years ago has spurred the others on. "Four years ago, we started a fad," boasted the foundation's Cathy Ludwig.

The follow-up this year, she said, "is going to be recommendations to all the departments and agencies. We're going to try to be a little more realistic -- what's doable." The suggestions will include eliminating some regulatory agencies, and recapturing "the moral high ground" for a new offensive on regulation.

At the Cato Institute, which describes itself as a "classically liberal, Jeffersonian" think tank, manuscripts by several authors are being compiled for a book entitled "Beyond the Status Quo: Policy Proposals for America." The topics include "An Agenda for Tax Reform" and "Freezing Trade."

Regarding the Heritage Foundation's 1980 book, Cato's Edward H. Crane said, "I guess maybe it did give us the idea. Ours is not nearly as legislatively oriented as Heritage's 'Mandate.' We're trying to stand back from the congressional fray and take a broader view."

Among other things, the Cato Institute articles recommend that workers be allowed to contribute up to 20 percent of their Social Security taxes to "super" individual retirement accounts, in exchange for a dollar-for-dollar income tax credit and reduced Social Security benefits. This proposal, according to the article, would not reduce Social Security revenues but would cut Social Security expenditures.

The Center for National Policy's major contribution so far has been its November tax policy paper, but the liberal think tank is also planning major policy papers on health care financing and environmental policy that it will release after Congress returns next year. Later, it plans a paper on interest rates and monetary policy, according to Ted Van Dyk, who heads the center.

The center is trying to help redefine the Democratic Party's agenda while retaining its liberal cast. Van Dyk said, "There is a feeling that Democrats are out of synch with the family that works and tries to pay the mortgage."

Other organizations chose to get in on the debate while the presidential campaign was under way. Earlier this year, the Urban Institute produced "The Reagan Record," the Brookings Institution offered up "America at the Crossroads," and the Stanford University-based Hoover Institution put out two books on foreign and domestic policy.

In the foreword to the foreign policy book, "To Promote Peace," Hoover director W. Glenn Campbell explained why the volumes were published in the spring of the national election year:

"Early publication of the essays in these volumes would contribute to the discussion of domestic and foreign policy issues of concern to the American electorate."