Krugman is totally right about one's values determining one's view on the welfare state. (I would say it's more a question of aesthetics.) It's not something you can really debate. Believe me, I've tried.
There really are people who believe in the "work or starve" / "let the devil take the hindmost" philosophy of social Darwinism, and they make up about 20 percent of the U.S. population and the core of the Tea Parties and Republican Party.
When it comes to the general welfare, they are not interested in outcomes, but rather in ideology, in establishing ideal, Randian rules of the game that don't impede the unlimited accumulation of wealth with no responsibility to give anything back. For them that belief is ironclad; it's beyond argument.
Krugman offers 5 issues, on the other hand, that do hinge on results, on empirical evidence. One side is definitely right or wrong. For these issues it's not a question of values or what's "right," but rather what's provably correct. Krugman observes that while liberals can and do disagree on these 5 issues, and still call themselves liberal without suffering ideological exile, conservatives must answer a certain way on all 5 or else be confined to an ideological reservation for "RINOs."
By Paul Krugman
May 25, 2013 | New York Times