Austin, Texas — The intraparty campaign scuffling of Mondale, Hart, and Jackson is short-term nomination politicking. It's not calibrated - yet - toward winning a presidential election, even though some polls currently show relatively strong Democratic strength against President Reagan. The President clearly maintains a strong grip on leadership popularity.
But, says issues and attitudes analyst Daniel Yankelovich with no hesitation, Mr. Reagan is vulnerable. Mr. Yankelovich heads the Public Agenda Foundation and the opinion-analysis firm of Yankelovich, Skelly & White. He took time during a public affairs conference at the Lyndon B. Johnson Library here last week to outline a scenario of ''risks'' and ''vulnerabilities'' which, he contends, could overturn Ronald Reagan's commanding lead.
The basic Yankelovich reasoning proceeds along these lines: ''The cornerstone of the President's support, and the source of all credibility, is that his economic policies are working. Now, if there should be signs that they are not working, if there are signs that the day after the election, the economic policy threatens to collapse, people are going to have some second thoughts.
''And the signs would have to do with the return of inflation, unemployment, a slowdown in the rate of recovery, higher interest rates, stock market decline, and, secondly, foreign policy crises in Latin America, for example, where the policy may possibly be read as a 'send-in-the-Marines' policy to deal with crisis.''
Mr. Reagan definitely can be beaten, goes this analyst's blueprint, if any one of three ''at risk'' groups in the United States should defect from Reagan.
One of them is composed of blue-collar workers who voted for the President in 1980.
Says Yankelovich: ''You have two sources of possible lack of confidence on their part: One is the economic issue - a feeling of unfairness that Mr. Reagan is the rich-man's candidate.'' The other is ''the feeling that the economy might not go in a way that will benefit them.''
Mr. Yankelovich, a social researcher for 25 years, acknowledges that foreign policy is a part of the President's strength with blue-collar voters.
''They feel that the President has been very assertive, doesn't permit himself or the country to be pushed around.'' There's a caveat, of course. This so-called ''macho'' leadership must be successful.
''If the President's policies are perceived as not being effective, then, of course, the confidence based on economics alone would erode,'' says Yankelovich. ''They are being held in solely by foreign-policy successes. If foreign-policy successes become blurred, these blue-collar voters could very easily go back to their normal, Democratic voting practices.''
The second group of ''vulnerables'' in the present Reagan alliance is the young, affluent, independent voters who consider themselves very pragmatic about political candidates.
''They are doing well,'' says Yankelovich. ''They give Reagan credit for combating inflation and for the recovery. However, if signs appear that Reaganomics - what George Bush in the 1980 campaign called 'voodoo economics' - is faltering, this group of voters . . . would walk away from Mr. Reagan in a minute. There's no loyalty there. There is just a pragmatic appraisal. Their support could change overnight.''
The third ''at risk'' group in the defeatable-Reagan scenario, is the women's vote - the gender-gap issue.
''Women are not as enamored of the macho foreign policy style as American men. They don't think it's the greatest thing in the world. They have more questions and concerns about the nuclear arms race, with the war and peace issues. It is only with respect to Reagan that there is the gender gap - it is not,'' warns Yankelovich, ''a general phenomenon.'' Women are uneasy, he says, with what they perceive as the President's attitude toward women: that they are important only because they are someone else's wife or daughter, not because they are individuals in their own right.
''I guess maybe they know from their own experience with men that aggressiveness and assertivness in response to everything is not always the most effective means of dealing with problems.'' Women constitute 54 percent of the electorate.
Each of Yankelovich's groups is distinct from the others. It is a given in his view of the current campaign landscape that if any one of these groups breaks ranks - let alone all three - Reagan could be beaten.
The central political question of the '84 campaign, as this veteran researcher sees it, is Reagan, and whether or not he is in control of the nation's destiny.
It's very clear to analyst Yankelovich: ''People will not be voting this year for a Democratic candidate. They're either going to vote for or against Reagan.''
As Yankelovich concedes, however, this one decisive issue of campaign '84 simply has not yet been raised - risked - by the Democrats. ''The Democratic candidate has to take the high-risk challenge of attacking directly the President's leadership style.''
With a pragmatic grin, Mr. Yankelovich adds: ''You don't fool around with Ronald Reagan.''