Sen. Alan Cranston of California seems to think he can win the Democratic presidential nomination by making a pro-nuclear-freeze position a central part of his campaign.
But current evidence from opinion polls and in the news media indicates that Mr. Cranston may be riding that issue too hard. Most Americans are not yet rallying behind a nuclear freeze - at least not with an intensity that would of itself win a nomination and turn an election.
Paul Warnke, the former US arms negotiator and arms control expert, provides some help in measuring the impact of the freeze movement in this country.
He supports a freeze, he says. But he makes it clear that he's no ''purist,'' someone who wants an immediate unilaterial US freeze.
Instead, Mr. Warnke says he favors a succession of steps as a prelude to a freeze, much as Sens. Edward M. Kennedy (D) of Massachusetts and Mark O. Hatfield (R) of Oregon do. And he stresses that the ''procedures that would be necessary to verify a production freeze have not as yet been developed.''
Warnke says he does believe the nuclear-freeze movement in the United States has been effective even to the point where ''politicians have to respond.'' Further, he says he feels that no candidate, Democrat or Republican, ''could run on an anti-arms-control platform'' in 1984 and win.
But when asked about Cranston's use of nuclear-arms control as the centerpiece of his candidacy, Warnke says (while affirming his belief that many Americans are rallying behind freeze issues): ''(The pro-freeze issue is) not going to be enough to win the nomination for anybody.''
Actually, Senator Kennedy was the first potential Democratic candidate to pounce on the pro-freeze issue. And, at first, there were Kennedy supporters who seemed certain that he had found, as some called it, ''the big issue'' - the one that could carry him to the presidency. But if Kennedy had any such hopes from this issue, he soon revised his estimates.
Warnke says he is convinced President Reagan is responding to pressure from the nuclear-freeze movement. He sees it in what he considers to be a softening of the President's criticisms of the Soviet leaders. And he sees it elsewhere:
''It is interesting to read, for example,'' he says, ''the current defense-posture statement as compared with last year's. I think that maybe we haven't changed their (the administration's) minds - but we have changed their form of address.''
At one point a reporter asked Warnke: ''Do you rule out a Reagan nuclear-arms compromise initiative?''
''No, I do not,'' he said. ''And it does seem to me, from reports I have read in the papers, that the vice-president has kept that option open.''
Looking at the political side: How would you view Mr. Reagan's ability to carry through on such a compromise with the Soviets?
Oh, there's no question but what he could carry through on a compromise. For one thing, he's commander in chief. And you're talking here about the deployment of American weapons in Western Europe. I can think of nothing that comes more clearly under his discretion.
As a conservative, wouldn't Reagan have an advantage over a liberal president - in terms of getting agreement to a missile compromise of this nature?
He clearly would. He certainly wouldn't lose any of the Democratic votes (in the Senate) that Carter would have lost with the Salt II treaty. And he would pick up a lot of the Republican votes that we (Warnke was President Carter's arms negotiator) could not get in 1979 for SALT II. If the President would say, ''this is what I want to do and this is the agreement I want you to approve,'' it is inconceivable to me that he would not win by a resounding majority - except for some extreme right-wing Kooks, that's all.