Both presidential candidates say their plans would provide health insurance to millions of people who lack it, but the problem is cost. With the federal budget deficit growing, Congress is likely to look at more limited and incremental moves to expand coverage. Analysts have come up with widely varying numbers: The nonpartisan Tax Policy Center projected that in the first year of full implementation, about 1.3 million uninsured people would gain coverage through the McCain plan, and about 18 million would under Obama's.