President Clinton, convinced the public is concerned about the increasing number of Americans without health insurance, yesterday proposed the biggest federal increase in health coverage in 35 years, a 10-year, $110 billion plan that would help millions of low-income people.

The plan would expand a relatively new federal program to subsidize health insurance for poor children to include their parents, while seeking to cover more children by making it easier to enroll them through schools and day-care centers. The president's plan also calls for tax incentives to encourage people to buy health insurance when they are between jobs or not quite old enough to qualify for Medicare, the government program for the elderly.

Taken together, the proposals represent the boldest health care initiative Clinton has offered since 1994, when public resistance to an ambitious plan overseen by the first lady resulted in one of his presidency's biggest setbacks. It also draws Clinton more deeply into this year's presidential race; the plan mirrors proposals by Vice President Gore to improve access to health insurance incrementally, rather than in somewhat bolder strokes, as proposed by Bill Bradley, his rival for the Democratic presidential nomination.

While the plan could face tough scrutiny in the Republican-led Congress, it underscores the extent to which Democrats have identified health care as the most potent issue to spearhead their hopes of retaking control of the House of Representatives and retaining the White House. Both Gore and Bradley have focused on ways to provide health insurance to many of the 44 million Americans who lack it, and Democrats plan to highlight the need for new prescription drug coverage and protections for patients in HMOs.

Clinton told reporters yesterday: "If you just look at what's going on in the election season this year, the public cares a lot about health care and they're talking a lot about it. . . . If enacted, this would be the largest investment in health coverage since the establishment of Medicare in 1965, one of the most significant steps we could take to help working families."

The initial reaction was cautious on Capitol Hill, where the GOP's 1994 takeover was partly fueled by voters' belief that the White House wanted a huge government role in decisions about choosing doctors and insurance. House Ways and Means Committee Chairman Bill Archer (R-Tex.) did not directly address the administration's plan, but noted that the major tax cut bill Clinton vetoed last fall had included incentives to help low-income people buy health insurance.

"Congress's top health care priority is helping more Americans get health insurance, but unfortunately, the president last year vetoed our plan to do that," Archer said in a statement. "I hope the president will work with us this year to make health insurance affordable and accessible for all Americans."

The bulk of Clinton's 10-year spending proposal--about $76 billion--would go to states as matching grants to provide health insurance for parents of children who qualify for the Children's Health Insurance Program. The state-based program, a product of the 1997 budget agreement, pays to insure children from families that earn up to 200 percent of the poverty level of income,, or about $33,000 for a family of four. The program was expected to help about half of the nation's 11 million uninsured children; about 2 million have signed up so far.

About 4 million adults would be covered under the new plan, and health experts say offering coverage to parents may make it easier to get children covered as well. Clinton's plan also calls for more assertive efforts to recruit children; not all who qualify are now taking advantage of the program.

"There are too many children who lose their hearing because an ear infection goes untreated, or wind up in the emergency room because they couldn't see a doctor in a more regular way," Clinton said. "Too many parents skimp on their own health to provide coverage for their children."

Henry J. Aaron, a health policy expert at the Brookings Institution, said Clinton has correctly gauged the public's sentiments, but that doesn't guarantee success in Congress.

"I think it will play quite well with the public," Aaron said of the president's proposal, "and for that reason may play poorly with the Congress. This is an election year, and the president may have a hard time selling to the Congress a program for which he will get most of the credit"--especially if Gore's name is repeatedly invoked.

Leading GOP presidential contender George W. Bush, asked about Clinton's proposal, replied: "This guy is a plan-a-day person."

White House officials were encouraged that the Health Insurance Association of America--which spent $15 million to oppose Clinton's 1993-94 health care plan--now is airing TV ads with the same "Harry and Louise" characters urging help in providing health insurance to all Americans.

Meanwhile yesterday, Sen. Edward M. Kennedy (D-Mass.) called for a similar approach as the first step toward reaching "all the uninsured on a realistic timetable." He said he would seek bipartisan support to pass it this year.

With his State of the Union address scheduled for a week from today, Clinton plans today to announce an expansion of the federal Hope Scholarship program, which offers tax credits to help eligible families pay college tuition. Hillary Rodham Clinton, seeking a Senate seat from New York, will join him, White House officials said.

Staff writer Helen Dewar contributed to this report.

Democrats' Health Plans

Bradley plan highlights

* Abolish Medicaid. Instead, poor people would get assistance in the form of tax subsidies, to be used to purchase health insurance.

* Allow Americans to buy plans through the Federal Employees Health Benefit Program.

* Allow all people, regardless of income, to deduct the cost of their health premiums if they are buying individual policies.

* Uncapped prescription drug benefit under Medicare.

Gore plan highlights

* Allow uninsured children above the the Children's Health Insurance Program (CHIP) eligibility cutoff to buy into Medicaid or CHIP.

* Allow uninsured people ages 55 to 65 to buy into Medicare.

* Tax credits for 25 percent of premiums for individuals buying their own insurance, or for small businesses joining purchasing coalitions.

* Prescription drug coverage under Medicare, capped at $5,000.

Clinton plan highlights

* Insure 4 million parents of children covered under Medicaid and CHIP.

* Provide a $3,000 long-term care tax credit.

* Allow workers as young as 55 to buy into Medicare and receive a 25 percent tax credit.

* 20 percent tax credit to small businesses to buy health insurance through purchasing coalitions.