In their drive to cut medical assistance to the poor while pushing tax breaks benefiting the affluent, congressional Republicans are following the lead of a group of governors who have championed this approach to balance state budgets. The strategy—reprising the supply-side economics of the Ronald Reagan era— has caught on with conservatives who say that lowering taxes for corporations and wealthy taxpayers will boost state economies. But the moves are sparking a debate in capitols from Arizona to Wisconsin to Maine over who is being asked to sacrifice and whether the strategy will produce more jobs.