President Carter's political strategists concede the Democratic race now may hinge more on Carter weaknesses than Kennedy strength. Mr. Carter's growing vulnerability over his handling of inflation and foreign affairs may be outweighing voter reluctance to back Edward M. Kennedy, though many perceive the senator as character-flawed.
With 60 percent of the Democratic delegates still to be chosen, the question from here on out -- asked by Republicans as well as Democrats -- is how long and deep the President's slide may run.
There is growing doubt among Democratic leaders whether a Carter-Mondale ticket could beat, say, a Reagan-Baker tandem in November.
Most pundits said the race was over after the President's drubbing of Senator Kennedy in Illinois last week. Suddenly, as the US looks toward the next major primary in Wisconsin, it seems likely to drag on until the remaining three-fifths of the primaries conclude this summer.
To prevent a repeat of the New York- Connecticut results -- which gave Mr. Kennedy 212 delegates and Mr. Carter 144 in the biggest one-day stake take so far -- the President may have to abandon his so-called "Rose Garden strategy" and appear on the hustings, despite his vow not to do so while the American hostages are held in Iran. If he does so, he will most likely appear in "town meeting" settings rather than in candidate debates.
For Senator Kennedy, the New York- Connecticut win gives him a solid 292-to- 210 lead over Mr. Carter among the East's 502 delegates. This is not enough to offset Mr. Carter's overall delegate lead -- 829 to 435, with 65 uncommitted, by Senator Kennedy's count and 859 to 410, with 60 uncommitted, by President Carter's count. But it bolsters Mr. Kennedy's claim that he can at least keep the President from wrapping up the delegate race before the last primary day, June 3, when 20.9 percent of the convention total will be chosen.
Mr. Kennedy will not campaign vigorously for next Tuesday's Wisconsin and Kansas primaries. He will focus instead on the April 22 Pennsylvania and Missouri contests, the Michigan April 26 caucuses, and the June 3 primaries in California, New Jersey, and Ohio.
In Wisconsin, Mr. Carter will face a second liberal, California Gov. Edmund G. Brown Jr., as well as Senator Kennedy on the ballot. The race there will be affected by a likely strong crossover of Democrats to the Republican ballot, where John B. Anderson and George Bush are hoping to hand Mr. Reagan another defeat.
The Kennedy campaign will thus key on the "industrial crescent" states from New Jersey west to Ohio and Michigan, where the effects of threatened recession would be most acute. Mr. Carter carried New York, Pennsylvania, Ohio, and Missouri in 1976 in his narrow 56 electoral vote win over Gerald Ford. Weakness in those states in 1980, the Kennedy campaign argues, would damage the Carter claim that the Democratic constituency is behind his White House performance. The Kennedy strategists, even after scoring their New York upset, are not assuming delegate momentum will swing convincingly enough their way to catch Mr. Carter by June. But they contend that if they are even close, they may be able to prevent a first-ballot Carter win by forcing a floor vote at the outset of the Aug. 10-14 convention challenging the rule that delegates must remain bound on the first ballot to the candidates they are committed to by primary results.
Meanwhile, the New York win will mean more cash for the Kennedy campaign -- enough to fuel a respectable drive in the remaining contests.
The Carter loss in New York and Connecticut is likely to draw more media and voter attention to Mr. Kennedy's differences with the President over domestic economic policy, Democratic leaders observe. Senators and congressmen involved in budget decisions -- weighing, they say, increased defense spending against cuts in jobs for youths and aid to industrial cities -- may now see greater risk in the President's policies, postponing a Capitol Hill consensus on the budget cuts.
A stampede of congressional endorsements to the President, anticipated if he had won in New York, now will also be delayed, Senate sources say.
The economic issue may prove most acute in states like Michigan, where the unemployment rate is the highest in the nation. Registration for Michigan's April 26 Democratic caucuses closed in February. The United Automobile Workers union, whose president backs Mr. Kennedy, registered many of its members before the deadline and is prepared to help turn out the vote for Mr. Kennedy.