The economic stimulus bill is dead, and blame is being cast about in Washington like so many lines off a Jersey shore charter. But the biggest losers may not be Senate Majority Leader Tom Daschle and House Speaker Dennis Hastert. No, the debacle's largest victims may prove to be giant health insurance companies, like Aetna ( AET), UnitedHealth Group ( UNH) and Oxford Health Plans ( OHP). After strenuous negotiations, Republicans and Democrats ultimately reached agreement on many components of the stimulus package: extending unemployment benefits, accelerating depreciation allowances for companies and speeding up the reduction of marginal tax rates. Health care turned out to be the dealbreaker.