The National Council on Disability, whose 15 members were nominated by Bush and confirmed by the Senate, reported this month that ''many Americans with disabilities feel that a series of negative court decisions is reducing their status to second-class citizens, a status that the ADA was supposed to remedy forever.''

Most disability advocates agree. But some fear that if Congress takes up the council's proposed ''ADA Restoration Act,'' it might end up making the law weaker, instead of stronger.

''In this political climate, is it smart to open up the ADA? We know that if we come up with our proposed changes, the other side will come up with theirs,'' said Curtis Decker, executive director of the National Association of Protection and Advocacy Systems, which includes 80 agencies across the country that represent people with physical, cognitive and mental disabilities.

Such concerns, while understandable, are misplaced, according to Lex Frieden, the council's chairperson. He said opposition to discrimination against persons with disabilities extends across party lines.

''It's a valid question to raise,'' said Frieden, senior vice president of the Institute for Rehabilitation and Research. ''In response, I would say that when the National Council on Disability first proposed the ADA [in 1988], a conservative, Ronald Reagan, was president, and there was a very conservative Republican Senate. But the law moved forward at a rapid pace and was signed by another Republican, the first President George Bush, in 1990.''

The independent federal advisory agency praised the law's successes in improving access to transportation, communications and buildings that serve the public.

But it said the ADA's protections for workers have been undermined since 1999 by a series of Supreme Court decisions, and lower court judgments that relied upon those decisions.

The decisions made it harder for people with disabilities to prove that they have disabilities, bolstered the defenses that can be used by those accused of discrimination, and limited the damages and legal costs that can be collected by those whose complaints are upheld.

That helps explain why only 35 percent of adults with disabilities have full-time or part-time jobs, the council said.

Charlotte Chenoweth, a registered nurse who analyzed medical records in Tampa, Fla., had a seizure and was diagnosed with epilepsy. Until she and her physician found the right combination of medications for reliable control of her seizures without side effects, she could not drive to work.

But Chenoweth lost her attempt to force her employer to let her work at home or to adjust her hours to coincide with the rides she could get to work. The judge ruled that Supreme Court decisions meant that since her epilepsy had been mitigated by the time her case came up, she was no longer protected by the ADA.

In fact, according to the council, Supreme Court decisions would have allowed her employer to fire her for having epilepsy, as long as the epilepsy was under control.

''This is true even if the employer . . . puts up signs that say 'epileptics not welcome here,' inaccurately assumes that all persons with epilepsy are inherently unsafe, or has the irrational belief that epilepsy is contagious,'' said the council's report, called ''Righting the ADA.''

In a similar case cited by the council, a pharmacist with diabetes was fired after he said he needed a half-hour off every four hours in order to take insulin and eat a small meal. It was ruled that because he could control his diabetes through such measures, he didn't have a disability covered by the ADA.

The revisions proposed by the council included the recommendation that the current ban on discrimination ''against an individual with a disability'' be reworded to ban discrimination ''on the basis of disability.''

''They would restore the original meaning,'' said Robert Burgdorf, a law professor at the University of the District of Columbia who worked on both the 1988 and the new drafts. ''If an employer discriminates against you on the basis of epilepsy or diabetes, the question should be whether you are being discriminated against, not whether you have epilepsy or diabetes.''

John Kemp, a Washington attorney who served on the council under President Clinton, endorsed the current council's plan. ''It shouldn't be true, it can't be true, that I - wearing four prostheses and using an electric scooter-wheelchair - could possibly be considered not covered by the ADA, because I have mitigated the limitations caused by my impairment.''