This week begins the election-year countdown for the Reagan presidency. With his State of the Union speech to Congress on Wednesday, followed by presentation of the fiscal 1985 budget and economic report next week, the President will set the stage and sound the themes for the 1984 Republican election campaign. When he formally announces on Sunday that he will seek a second term - assuming he does - the political battle will be joined.
There is no doubt about Mr. Reagan's basic message. From the powerful podium of his office, the President already is trumpeting what he considers to be the achievements of his administration: a resurgent economy at home and a more assertive America abroad. In contrast to three years ago, when he assumed the presidency, Reagan says confidently, things are better and the nation is launched on a new course.
At the same time, with his political antennas attuned to Democratic critics and to an ambivalent public mood, the President is beginning to outline the chores of a second term.
''We still have much to do - wringing out more waste and fraud in government, putting more Americans back to work, attacking the federal deficit, getting inflation and interest rates down still further - these and other great labors lie before us,'' he told a gathering of political appointees last week.
As he seeks to control the political debate in the weeks and months ahead, say GOP strategists, the President will have to respond to concerns on both the economic and foreign policy fronts.
The latest economic figures, for instance, suggest that the President has something to shout about but cannot be entirely free of worry about the future. On the positive side, inflation rose by only 4.3 percent in 1983, according to the Commerce Department. Also, the economy as measured from the fourth quarter of 1982, the beginning of the recovery, through the same period of 1983 grew a strong 6.1 percent - about the same as in previous recoveries. Personal consumption and investment in new plant and equipment also rose at healthy rates. Personal disposable income was up 3.2 percent in 1983.