A bipartisan group of senators may quietly succeed, if only incrementally, where President Clinton's frontal assault on the health-care system failed. The Senate Labor and Human Resources Committee today passed health insurances changes that would make it easier for millions of Americans to keep health insurance coverage when they switch jobs or get sick -- one of Clinton's central reform goals. Under the Health Insurance Reform Act, which should reach the Senate floor this fall, no one who continues to pay insurance premiums can be excluded for health reasons or saddled with a new waiting period simply because of a job change. Though the insurance industry has argued that the requirements would drive up premiums, mainly by keeping more sick people insured, Sen. Nancy Kassebaum (R-Kan.), a co-sponsor, said: "Most Americans would rather see a modest increase of premiums in exchange for peace of mind." Sen. Edward Kennedy (D-Mass.), the other chief backer, said he would still seek Clinton-style universal coverage, "but it's important to deal in the real world."