Washington — Even while President Carter basks in the sunshine of his Southern primary success, his backers have a worried eye out for clouds threatening his candidacy.
At the moment, the Carter delegate tally has resumed its pre-Massachusetts impressive lead against Senator Edward Kennedy's. On March 11, with 10 percent of the convention delegates at stake, Mr. Carter won by impressive popular vote margins in three Dixie Democratic primaries -- 2-1 in Florida, 10-1 in his home state of Georgia, and 6-1 in Alabama.
He also won a majority of delegates the same day in Democratic caucuses in Oklahoma and Hawaii, with the outcome close in Washington State Caucuses. In early returns, he had lost Alaska to Mr. Kennedy, where less than half of 1 percent of the convention's delegates were at stake in precinct caucuses.
Through March 11, Mr. Carter probably had garnered two-thirds of the 626 delegates chosen so far, orm about 12 percent of the 19 percent of 3,331 Democratic national convention delegates elected. He figured to add to his margin in the Delaware caucuses (March 12), the South Carolina and Mississippi caucuses (March 15), and the Puerto Rico Democratic primary (March 16), before the crucial Illinois primary on Tuesday, March 18.
The winning margin in Illinois again will likely go to the President. By then, 28 percent of the convention delegates will have been chosen.
Not until the New York and Connecticut Democratic primaries March 25, when an other 10.1 percent of the convention total will be contested, does the President's delegate momentum appear likely to be interrupted by a significan Kennedy win.
And from then on, Kennedy strategists concede, the senator would have to win a remarkable 55 percent to 45 percent vote over President Carter -- definitely taking Michigan, Ohio, New Jersey, and California -- to win a majority of delegates to the Aug. 11-14 convention in New York City.
Nonetheless, the Carter forces are worried. Signs of presidential vulnerability seem unmistakable.
Because of inflation, which troubles everyone, threatened budget cuts in social programs that alarm liberals, the administration's bungled United Nations resolution vote on Jerusalem that vexed US Jews, the lingering Iranian hostage and Soviet-Afghanistan impasses -- evidence appears to mount before voters' eyes again that Mr. carter may be an ineffectual leader.
The President's approval rating nationality is slipping. Only four in 10 of florida's Democratic voters rated Mr. Carter's performance good-to-excellent, according to NBC interviews of those leaving the polls. A CBS poll gave Carter a slim 45 percent to 42 percent favorable rating among Democrats, but a lopsided 79 percent to 16 percent negative margin among Republicans.
Much of Mr. Carter's ballot edge over Senator Kennedy appears to be "hollow," the President's strategists concede. But the softness of the Carter vote does not translate directly into strength for Senator Kennedy. Only among liberals and Jews does the senator seem to gain from Mr. Carter's perceived weakness. And in Illinois these two groups appear attracted to the candidacy of Republican John Anderson.
Senator Kennedy shows no sign of letting up on his challenge, however, even if the delegate edge continues to slip from his grasp. At stake for him is the leadership of the liberal wing of the Decmocratic Party, control of party decisions on domestic and foreign issues at the convention, and the possibility of his running again for the White House in 1984.