National Review has declared that Donald Trump is no conservative. I think the publication is right. While a lot of what Trump advocates for overlaps with conservatism, maybe even more than National Review would like to admit, modern conservatism as a political philosophy diverges so much from Trumpism that he's not one of them. If conservatism is a political philosophy, it is not one Trump shares.
But Trump's followers would certainly call themselves conservative, and maybe they have a claim on the label. They are just viewing conservatism differently. As Rush Limbaugh, who should know what he's talking about, explained:
If conservatism were the glue, the belief and understanding of deep but commonly understood conservative principles, if that's what defined people as conservative and was the glue that made the conservative movement a big movement, then Trump would have no chance. ... Therefore, it's safe to conclude that there are other things at play here that make people conservative. ... The thing that's in front of everybody's face and it's apparently so hard to believe, it's this united, virulent opposition to the left and the Democrat Party and Barack Obama. And I, for the life of me, don't know what's so hard to understand about that.
The distinction is what political scientists might call the difference between operational or philosophical ideology and symbolic, affective or identity-based ideology. For National Review, conservatism is a set of principles and values, interpreted as they have interpreted them. A liberal might argue that they don't interpret those principles correctly, but they have the way they have, and that's conservatism.
For Trump backers like Sarah Palin, conservatism is an identity. It's tied up with symbols and grievances, pitting allies against enemies. Palin's endorsement included repeated references to those grievances.
There is obviously a relationship between the two. The symbols and grievances are drawn from those described by conservatism. Most people with a conservative identity do also agree with the philosophy. Ideologies always serve to define a coalition, because people are drawn to them for different reasons.
But research suggests that many who consider themselves ideologically conservative or liberal do not actually hold the policy positions that we would expect them to. They may use the arguments and language of the ideology, but it's the identity that drives them, not issue positions.
This is not necessarily an indictment, by the way. Politics is about allies, and reference to an ideological identity is a shortcut in the same way that a partisan identity can be. Not everyone is a political philosopher. The actual political philosophies of liberals and conservatives are important in shaping policy proposals, but so too are the political identities.
Identity ideologues may be part of the mechanism by which philosophical ideologies become important in politics, because self-described conservative voters do tend to vote for self-described conservative candidates, even if the voters' self-descriptions are less accurate than the candidates'.
If so, it's very understandable that National Review is irked about how much credit Trump may be getting for simply identifying with a brand he doesn't represent very well.