For a decade Henry Cisneros has been the pre-eminent Hispanic leader _ a successful mayor, an articulate speaker, a thoughtful politician, a powerful role model. At the height of his prestige, he is moving to the sidelines, maybe even getting out of politics. He's turned down an offer to speak at the Democratic National Convention, quashed any talk of the vice presidency and ruled out trying to spread his ``San Antonio Miracle'' with a statewide race in Texas in 1990. Even as national attention turns to the power of Hispanic political clout this year, Cisneros says he may not seek re-election as mayor. Cisneros said of his move out of the national arena, ``It's a decision that I've made.'' ``For the moment my total and exclusive focus is on San Antonio issues,'' he said. ``We're in a period of tremendous resurgence in San Antonio after the Texas slump and we have many, many initiatives here that are setting this city in position for the long run.'' His attention is also focused on a year-old son with a congenital heart defect who will require extensive surgery at about the same time as the 1990 campaigning season. Cisneros also talks regularly with two businessmen about joining them in a corporate venture. To other Hispanics leaders across the country, not having Henry Cisneros out front carrying the torch will be a setback. ``He leaves a huge vacuum,'' said Los Angeles City Councilwoman Gloria Molina. ``His soft-spoken yet direct way is what we need and I don't know if anyone else can sit down with presidential candidates, labor leaders, or whoever and look them in the eye and not give in. ``As he steps to the sidelines, he'll be sorely missed,'' Molina said. ``Everyone thinks it's a shame but they respect his priorities,'' said Harry Pachon, director of the National Association of Latino Elected and Appointed Officials. Cisneros, interviewed four years ago by Walter Mondale as a possible running mate, says he'll campaign for Democrat Michael Dukakis this fall, and he'll announce Sept. 15 his decision on a possible fifth term as mayor. He often points out he's never put himself forward as any sort of official Hispanic spokesman or leader, and says he turned down a chance to address the Democratic National Convention in Atlanta because he just didn't have the time. ``To take weeks off to prepare a quality major speech and then deliver it just adds to the weight of what I need to do here on things I have promised to do,'' including projects on water, education, drugs and a domed stadium, he said. He says he doesn't see a gap in Hispanic political leadership. ``I can see from the Jesse Jackson experience that it might be useful to have someone who could bring people together and speak for people in a way that Jackson is doing,'' Cisneros said. ``But frankly, the Hispanic community doesn't lend itself to that. There are more differences in the Hispanic community than there are in the black community. ... My sense is what is happening is very productive and that is a lot of leadership is being developed across the country.''