Shorter Sebastian Mallaby: Democrats have no principles because they won't cut Social Security for married low-income people. Snark aside, I bring this up because Mallaby and many of the entitlement-reform-obsessives around Washington are missing the point about fast-growing government spending. The fastest growing part of the budget are interest payments on the national debt. For more, Daniel Gross has a great article in Sunday's NYT explaining why interest payments have taken off. Additionally, unlike entitlement spending, high interest payments (and the deficits that help drive them up) serve no social or economic purpose five years into an economic recovery. In fact, it's even more likely that they are an impediment to growth and crowd out spending for other public priorities. Mallaby's perspective is particularly ironic considering that the Bush administration's adamant refusal to increase taxes or lift the payroll tax cap for high-income earners forces any proposed solutions to either cut benefits (hurting more than just Mallaby's self-professed Democratic strongholds of "poor women and minorities") or add even more debt to the country's books - further imperiling other social spending through even higher interest payments. Now that would be fiscally irresponsible.