Ross Douthat and James Capretta urge Republicans to extend the payroll-tax cut passed in 2010. I am very sympathetic to their argument, but I would raise one political caution: Republicans should be careful about providing Democrats an opening to say that the former are endangering Medicare and Social Security. That charge might be inaccurate and even hypocritical (since the original cut was the Democrats’ idea), but it could still have bite. If the Democrats propose an extension, going along with it makes sense. I think both Douthat and Capretta, to the extent they’re making a case based on political strategy, are underselling the risks for Republicans of being out front in favor of a cut.