"In this case, the Federal Government has taken upon itself the burden of financing practically all medically necessary expenditures. One category of medically necessary expenditure has been singled out for exclusion, and the sole basis for the exclusion is a premise repudiated for purposes of constitutional law in Roe v. Wade. The consequence is a devastating impact on the lives and health of poor women. I do not believe that a Constitution committed to the equal protection of the laws can tolerate this result. I dissent."