"I REALLY BELIEVE it's time I put my family first," said North Carolina's Jim Hunt, explaining why he decided not to run for John East's Senate seat next year. No doubt that is a reason he didn't run for a Senate seat he had an excellent chance to win. Mr. Hunt, after all, got 48 percent of the vote against Jesse Helms last year, when Mr. Helms spent more money than any other Senate candidate in history and Ronald Reagan was winning 62 percent at the top of the ticket. But one has to wonder whether Mr. Hunt really wanted the job. He is one of at least 10 popular current or recent governors who decided not to run in 1984 or 1986 for Senate seats they had reason to believe they could win.

For example, Republicans Lamar Alexander and Pierre du Pont declined to take on Democratic senators in what turned out to be the Reagan landslide year of 1984. This year, Mr. Hunt joins the Democratic governors of Arizona, Arkansas, Colorado, Oklahoma and South Carolina, in not running. Only one governor, Jay Rockefeller of West Virginia, won a Senate seat in 1984; only one, Bob Graham of Florida, seems sure to run in 1986. Has the Senate, once almost a credential required for a presidential race and the cynosure of every ambitious politician, lost its attraction to governors?

The answer seems to be yes. Talk to almost any incumbent governor today, and you see a glint in the eye when the conversation turns to substantive issues. Governors have pushed education reforms and have had the satisfaction of seeing test scores rise; they have passed economic development programs and have had the satisfaction of cutting ribbons on new job sites; they have worked on problems ranging from water supply to building prisons and have had the satisfaction -- and have reaped the political rewards -- of getting visible results. Not so for most senators. As block grants are substituted for categorical programs, as the challenge has come to be in paring the budget down, their work seems less challenging and less interesting to many. Governors would just as soon enjoy the fruits of the private sector or run for president.

One other factor is in operation: their very successes as governors may hurt them in Senate races. This was especially visible in the Hunt-Helms race in 1984. Governors try to reach consensus on policy and get wide support, which leads them to take positions in the political middle; a senator such as Mr. Helms is free to take clear positions at one end of the political spectrum. Mr. Helms made a virtue of this forthrightness and in many of his ads taunted, "Where do you stand, Jim?" The result is not a particularly happy one: the Senate ends up with more ideologues than it needs, and fewer members with experience and success in the front lines of governing. The governors will presumably get along well enough without serving in the Senate, but the Senate might do better with a few more governors.