Diplomacy and political endorsement

In his dozen years in the Senate, Jesse Helms of North Carolina has earned a reputation as an innovator. The Republican, running for reelection in a bitter struggle with Gov. James Hunt, had earlier devised a strategy of using roll-call votes to put on record his Senate opponents on issues like abortion, so that opponents could be targeted in their own reelection efforts. And he developed a powerful direct-mail organization that collects funds to aid candidates he wishes to support.

But Mr. Helms's latest innovation, soliciting the endorsement of 22 noncareer ambassadors - ''all appointees of President Reagan and ... on the front line of the president's foreign policy'' - reaches too far; it meddles with what should be nonpartisanship in the appearance of the nation's diplomatic team abroad, and it compromises fidelity to the President's policies in substance. If indeed Mr. Helms were to succeed Sen. Charles Percy of Illinois as Senate Foreign Relations Committee chairman, he might feel encouraged to attempt more such independent endorsement of Helms positions.

Helms has distinct views on a wide range of foreign-policy turf, from Pretoria to Taiwan. His career has been built on effective tactical maneuver, rather than on support for Republican majority positions. Senate foreign-relations chairmen are far from all-powerful. But they do exercise considerable control over personnel. If Mr. Reagan is returned to office, and if new secretaries and undersecretaries of state, ambassadors to the United Nations , and so forth are nominated, the committee chairman could decide the timing and witnesses for hearings. Appointments could conceivably be blocked in Senate hearings.

Mr. Helms is considered a likely candidate for the presidential nomination himself in 1988. The ambassadorial endorsements, even though predictably denounced by a group of former ambassadors, may have been intended as much for that ambition as for rescuing his Senate seat. Either way, it would have been in his own interest to avoid the appearance of compromising the status of diplomats now serving another President. He certainly would not welcome any poaching of diplomatic allegiance were he in the Oval Office.