It would seem pretty obvious that politicians respond to the concerns of interest groups. A successful politician manages to garner the support of enough powerful interest groups to get the money and votes to put himself or herself in office. They don't have to pass tests in political philosophy.
Therefore it is peculiar that a NYT article would refer to the "the core philosophical disagreements" between Republicans and Democrats. It is not clear what this means since there is little evidence that either side is guided by philosophy rather than political expediency. Philosophy does not win elections.