I don’t think that is what Matthew Yglesias is trying to say here but I think he makes a good point as to why right leaning politicians do well.
The basic idea of a center-right party is that it represents a coalition of the business establishment with the socio-cultural mainstream. That tends to give you a dominant position in politics.
You can see why a pro-business politician that is socially liberal will probably do well, businesses are happy to give them money, and for the most part people want to be left alone. This makes me think that what is really dragging the republican party down are the social conservatives; although I am not sure that conservatives are really pro-business so much as pro rich guy and that might be why they need the social conservatives for electoral success.