The Senate health-care bill would raise effective marginal tax rates on lower and middle-income singles and families up to 41%. The effective marginal tax rate is the answer to the question: "If I earn $1 more, how much less than $1 do I get to save or spend?" If you can keep that full dollar for your disposal, the effective marginal tax rate is zero. If earning another dollar does not raise your disposable income by even a penny, the effective marginal tax rate is 100 percent. Consider, then, the figure below constructed for a two-earner family with two school-age...