A highly cited model of protectionism is the "protection for sale" model or Grossman and Helpman. (For an [updated] evaluation of that model see for instance the Advanced International Trade textbook of Feenstra.)
However this model seems pretty limited to me in the view of Trump and Brexit. Modelling just lobby/industry groups carving/buying out increased protectionism in their own niches seems overtaken by events in which narrow democratic majorities capture the entire trade policy in a protectionist matter. Now (other) industry/trade groups seem to fight for niches in the opposite direction, i.e. being exempted from the overall tariffs increase; see Apple as an example.
Are there economic models that account for this new reality? (To some extent, this requires only a fairly trivial extension of "protection for sale", i.e. in an elevated protectionist environment, there will be groups lobbying for less protectionism, and their [anti-protectionist] niche-carving success will depend on their political clout (as a mirror of the process of buying protectionism). On the other hand, the conditions for a majoritarian capture of [increased] overall protectionism in a democracy doesn't seem so trivial.)