The "Mainstream Coalition," a bipartisan group of 16 senators working on a health-care compromise, may not have as much influence as Inside-the-Beltway hype has suggested. The coalition, led by Sen. John Chafee, R-R.I., hoped to present Senate leaders today with a bill designed to break the impasse between Republicans and Democrats. It would put cost controls on the insurance industry, and take employers off the hook of having to provide bill for coverage. But this morning, Congressional Budget Office Director Robert Reischauer said their numbers didn't add up. Chafee called the briefing "sobering," but added: "I certainly don't want to throw in the towel yet." TIME Washington correspondent Dick Thompson was less optimistic: "This could derail them."