President Reagan is positioning himself for reelection by shifting his administration's emphasis from domestic to foreign affairs. Finally freed from what he saw as the need to give the domestic economy almost total attention, he is looking abroad.
True, growing urgencies in the Mideast, in Central America, and in East-West relations appear to have forced the change. But Mr. Reagan's decision to give foreign affairs his No. 1 priority has been a conscious one. According to those close to the President, his decision has been conditioned by the opinion that if he is to be reelected he must make a mark in his dealings with other nations.
The President is understood to believe the doctrine - espoused by pollster Lou Harris, among other political observers - that Republican presidential candidates win on foreign policy while Democratic candidates win on domestic policy.
Thus, the President's new, deep involvement in foreign affairs brings with it added, if not almost conclusive, evidence that he is likely to run again.
The President's foreign policy scorecard is just beginning to be tallied. He has gained a tentative point from Secretary of State George P. Shultz's ability to broker an agreement between Israeli and Lebanese leaders on the withdrawal of Israeli troops from Lebanon. But progress toward an arms pact with the Soviets seems stalled.
But in Central America, Reagan's team has definitely scored a tactical political victory here at home. Democratic resistance to Reagan's involvement in El Salvador and Nicaragua - particularly Connecticut Sen. Christopher J. Dodd's TV rebuttal to Reagan's April 27 address to a Joint Session of Congress - has given the President the high ground on the issue.
The Democrats are split over whether to challenge Reagan in Central America or to give him what was once a traditional bipartisan support.
Of Senator Dodd's challenge and opposition to the President among other Democrats, Democratic House majority leader James Wright said at a press breakfast:
''I'm sad about that. . . . I do believe in a bipartisan foreign policy. . . . I don't think there should be an official Democratic position, going out and trying to find fault with what the President says on foreign policy. Dodd didn't speak for a lot of other Democrats. And we're getting a lot of flak because of that.''
The growing view among seasoned observers here is that the divisiveness in the Democratic Party over the President's Central America policy could carry over to the 1984 presidential campaign.
Reagan set the stage for possible political gain by ending his televised address with the question: ''Who among us would wish to bear responsibility for failing to meet our shared obligation?''
Many Democrats shuddered when they heard this warning.
Of the Dodd rebuttal, a leading Democratic strategist says: ''You should let the President have the spotlight. If we now have an intramural contest among the Democrats, it just makes the President's work easier.''
And of the open Democratic challenge to Reagan's Central America policy, a man who has been closely identified with several Democratic presidents said: ''It could turn out to be terribly damaging to the party in 1984. It's potentially an explosive issue.''
Not all Republicans hail the President's handling of foreign policy. One highly regarded Republican agrees that Reagan ''is in a position to blame the Democrats if El Salvador is lost.'' But he adds that the President has ''failed in providing leadership in national security affairs. He resembles a comet without a tail. I don't see the follow-through in his presidential initiatives abroad - there is no tail to it. He seems to have an inability to produce a follow-through. He may have the El Salvador issue now. But, because of lack of follow-through, he may lose El Salvador.''
On the President's decision to position himself for running again, the presidential and GOP pollster Robert Teeter says:
''The President may well be positioning himself for 1984. The polling data thus far have shown the public uncertain of what the President is doing in foreign affairs. It is not so negative as it simply is soft - uncertain. So I feel the President's moves now clearly are directed toward firming this public attitude up and in his favor.''
Mr. Teeter joins other veteran presidential watchers here who say that incumbent presidents usually can benefit - at least intitially - simply by taking initiatives in foreign policy.
Therefore those who seek out public attitudes say they expect that Reagan will make some political hay - and gain some temporary approval - for his new initiatives in Central America and the Mideast.