For many years there has been one overwhelming rule for people who wanted to be considered serious inside the Beltway. It was this: You must declare your willingness to cut Social Security in the name of “entitlement reform.” It wasn’t really about the numbers, which never supported the notion that Social Security faced an acute crisis. It was instead a sort of declaration of identity, a way to show that you were an establishment guy, willing to impose pain (on other people, as usual) in the name of fiscal responsibility.

But a funny thing has happened in the past year or so. Suddenly, we’re hearing open discussion of the idea that Social Security should be expanded, not cut. Talk of Social Security expansion has even reached the Senate, with Tom Harkin introducing legislation that would increase benefits. A few days ago Senator Elizabeth Warren gave a stirring floor speech making the case for expanded benefits.

Where is this coming from? One answer is that the fiscal scolds driving the cut-Social-Security orthodoxy have, deservedly, lost a lot of credibility over the past few years. (Giving the ludicrous Paul Ryan an award for fiscal responsibility? And where’s my debt crisis?) Beyond that, America’s overall retirement system is in big trouble. There’s just one part of that system that’s working well: Social Security. And this suggests that we should make that program stronger, not weaker.

Before I get there, however, let me briefly take on two bad arguments for cutting Social Security that you still hear a lot.