Each person who thinks she loves America loves her own America so Paul Krugman’s question is not even rhetorically interesting.
The tribe he is referring to – the “white Christians” of America – is still by far the largest “tribe” in the country, and if it were unanimously fearing that its interests might run counter to the interests of other constituent “tribes,” that conflict could not be solved by naming, shaming and blaming.
But the outsized irony that probably escaped the great economist is not about that. Suppose “the tribe” were used in the Urban Dictionary sense, “Democrats” and “Republicans” reversed, and the article, with other obvious adjustments, had appeared in a right-wing publication some time before 1960.
It would have fit right in.