Fast-Moving Kemp Finds Brakes Applied at HUD : His innovations have been rejected by Congress and ridiculed at the White House, but he still has his eye on the presidency.

WASHINGTON — As a Republican congressman from Buffalo, N.Y., Jack Kemp won a reputation for being indefatigable--a frenetic idea man, an evangelist for free-market economics and the darling of GOP conservatives. Almost nothing, it appeared, could hold him back.

Today, after two years as President Bush’s secretary of housing and urban development, Kemp still retains all those traits, but he shows increasing signs of strain from the constraints of his office and some frustrating setbacks.

Despite Kemp’s close ties to Congress, lawmakers have flatly rejected his efforts to increase federal funding for some of his key programs, dealing a visible blow to his drive to promote new conservative ideas for aiding the poor.

He has suffered open ridicule from inside the Administration for his efforts to push new concepts for transferring more “decision-making power” to housing-aid recipients. Last winter, Budget Director Richard G. Darman loudly disparaged the notion as unworkable.

And, just a few weeks ago, the State Department publicly took him to task for meeting with Israeli Housing Minister Ariel Sharon, who has been an outspoken critic of the Administration, without White House permission--suggesting pointedly that he stay out of foreign policy.

To top that off, Kemp, who for years was a favorite of the Republican right wing, has begun to get decidedly mixed reviews from former supporters, some of whom now scorn the housing secretary as a “big-government conservative” and warn that it would cost billions to carry out his ideas.

Kemp admits that he is frustrated, although not necessarily discouraged.

“It’s a struggle,” he conceded. “I’m cautiously optimistic that the power of home ownership will overcome the social welfare bureaucracy and the liberal Democrats in Congress . . . but lots of public housing authorities don’t agree.”

The graying Kemp, who will be 55 this July, clearly has the presidency on his mind. He ran unsuccessfully for the GOP nomination in 1988, and many politicians think Kemp may try for the White House again in 1996.

The former professional football quarterback still seems to prefer calling the plays. And he never loses sight of his own goal-line.

The housing secretary is still campaigning fervently for a cut in the capital gains tax--although the White House already has signaled that it no longer regards this as a high-priority item.

And, in what some Republicans view as an end run around the White House, he more recently has advocated a cut in the Social Security payroll tax--a Democrat-supported move that Bush already has denounced as a threat to the solvency of the Social Security system.

Admittedly, not all is going awry for the ebullient Kemp.

He has clearly scored points for cleaning up his department, which was mired in scandal after the tenure of former Secretary Samuel R. Pierce Jr. Kemp initiated sweeping changes to help keep political influence out of HUD’s decision-making process.

And, by giving federal housing programs the highest profile they have had in a decade, he has won the grudging admiration of such industry groups as the National Assn. of Realtors and the National Assn. of Home Builders.

In some ways, being secretary of HUD is an ideal platform for an ambitious Republican. By being in charge of billions of dollars of housing grants, Kemp has been able to promote conservative ideas to replace traditional Democratic-backed entitlement programs.

House Republican Whip Newt Gingrich (R-Ga.), one of Kemp’s biggest fans on Capitol Hill, said Kemp’s innovative ideas on transforming inner-city ghettos into enterprise zones and bastions of private property were being stifled by the Democratic leadership in Congress.

“The question is whether he can get a strong public reaction to overcome this resistance,” Gingrich said. “He’s tackling one of the hardest problems there is, and he’s showing that conservatives can care about everybody.”

Even so, some questions remain about his qualifications for the presidency--even among pedigreed conservatives.

Stuart Butler, director of domestic policies studies at Heritage Foundation, who is an admirer of Kemp, wonders whether he has “the killer instinct” to win a presidential campaign. And, he adds: “The jury’s still out on whether he can really manage.”