Whether Margaret Thatcher's great Conservative Party victory in Britain foreshadows a similar triumph for Ronald Reagan next year will be the subject of continuing political analysis and speculation. And, of course, all of it is inconclusive.

Whatever the similarities and differences between U.S. and British political conditions--and there are as many on one side of the equation as on the other--one common factor stands out. It is the most illusory but perhaps most significant: how the voters feel about their respective leaders.

It is not so much their policies that count. It is their personalities.

In saying that, I do not mean to denigrate the wisdom or sophistication of voters on either side of the Atlantic. Nor is it true that policies are unimportant. I do mean to suggest that the way voters relate to Thatcher and Reagan is politically powerful. In neither case are voters indifferent to them.

To Britons, she is Maggie, a strong presence. To Americans, he is Ronnie, a strong president.

You can disagree passionately with the way they have handled the major issues, and certainly many voters here do when they think of Reagan, but not about another political fact. Thatcher and Reagan have solidly established themselves in the minds of the people as leaders.

For Reagan, that personal feeling is perhaps his strongest political asset. Whether it will be enough to carry him to a Thatcher-like reelection triumph, assuming he runs, looms as one of the more intriguing questions in the 1984 presidential puzzle.

During a recent grass-roots sample of citizens in the Midwest, two dominant feelings about Reagan emerged. They were in sharp conflict and often expressed by the same person.

He has, it was said, made people feel better about their country. As a doctor put it, Reagan "has restored the dignity of the presidency." There were nods of agreement from neighbors gathered in the living room.

Yet that same conversation brought out the belief that Reagan's presidency has been unfair, that it has resulted in people being hurt unnecessarily. "I have not been affected personally by the policies he has put in," said another man, a banker who also voted for Reagan last time, "but I have seen what it has done to other people."

To which a housewife said: "I think the man is blind to the pain and suffering of the country."

With Reagan, as with no other president in modern history, these contradictory feelings are at war with each other. Other presidents have aroused strong emotions, but seldom is the split between positive and negative feelings about them so complex and interwoven as with Reagan.

If you examine blocs of voters needed to win presidential elections, Reagan appears to be highly vulnerable today. He is far weaker among them than in 1980. Put aside the blacks, among whom Reagan has not the slightest chance of gaining support, and concentrate on three other major groups. They encompass what I term the three Ws: women, workers and Watt.

Attitudes of women voters toward Reagan have been much discussed, and for good reason. Women tend to be more critical of Reagan than men in such areas as the impact of the recession on people's lives and prospects of greater U.S. involvement in places such as Central America. You will find this to be so in conversations with husbands and wives together or separately, and with individual women, single or otherwise, housewives or professionals.

Workers, union or not, were attracted to Reagan, and large numbers voted for him in 1980. The hope was that they would become part of a permanent coalition forming around Reagan. They were destined to become key elements in America's new political majority. The most that can be said about that prospect now is that it is far premature, if indeed it ever had a chance of becoming reality. Next to blacks, this group expresses the greatest anger and sense of betrayal about Reagan today.

As for Watt, the third W, I do not mean merely the reaction of voters to the combative and controversial interior secretary. I mean the depth of concern they express about environmental questions and the way they critically link what they see as Watt's policies with Reagan's beliefs. Here lies a negative, clean and clear, for a Reagan reelection campaign next year, and one that I suspect carries as much potential damage for the president in the crucial electoral votes of the western states as anywhere.

Despite these considerable negatives, my guess is that if Americans were voting today they would follow the British example and reelect their leader on the basis of their personal feelings again.

Some weeks ago, a Democrat prominent among the prospective presidents was privately assessing his party's chances in 1984. His assumption was that Reagan will run and be extremely hard to beat.

"The best thing we have going for us now," this man said, "is that the election is more than a year away."

If it were now, he believes, Reagan would win. Given another year, though, voters' attitudes could be different. Large blocs of the unemployed would still be with us, and the disparity between rich and poor would be greater and more evident. The prospect of inflation and interest rates rising again along with the recovery would dampen enthusiasm for another four years of Reagan. The policies Reagan has followed at home and abroad would be seen for the failures they already are.

Thus, anyway, goes the argument, however much wishful thinking it might contain.

Part of the puzzle is missing, and here an analogy between Reagan and Thatcher seems apt.

Both are regarded as strong leaders, but with a difference. For all of the similarities in their economic policies, in their determination to change the course on which their nations have long been steering, their leadership has sent different sorts of signals to the voters.

Thatcher never said it would be easy. With typical British forbearance, she has asked Britons to bear the price of hard times for a better tomorrow. Tighten your belts, stiff uppers and all that. Reagan's sunny attitude has conveyed the feeling all can be done without pain. Who needs a national call to sacrifice? Sacrifice for what? We have the easy answers. Nobody's hurting. Nothing's unfair, except our critics. Everything is wonderful.

In the end, how voters feel about those questions involving their strong and pleasing president will probably determine the outcome of the election.