It appears that Brexit has unleashed a great cleaning of the British political theater system. One positive item in all of this is the removal of David Cameron as prime minister. Cameron stepping down is the death of Cameronism. The death of Cameronism has a secondary effect here in America because it ruins one possible path for the GOP after the Trump phenomenon.
Cameronism was discarding social conservative ideas, picking some specific progressive platform ideas to push and then pushing neoliberal economic policies. Despite the liberal positions that Cameron supported, he was considered a wicked, evil conservative. It is like the GOP, which is already the Diet Coke version of the Democrats, turning into Coke Zero. In the United States, one could easily see this as the path for the GOP had Trump never showed up considering how fast the GOP rolled on gay marriage and even trans issues. Cameron's referendum blunder and shame at not being able to rig a vote properly, should be the end of that style.
Brexit was not a quirky oddball issue, but a major marker in the Nationalism vs. Globalism fight. Dominic Cummings was one key figure behind Leave, and to have such a push for Leave, there were deep interests that wanted it to happen. If the fight is one about sovereignty and the idea of controlling one's destiny, then it clues the GOP actors, donors and interests away from going a Cameron route and in the direction of nationalism.
This modern form of nationalism is different from the 19th century version. There is no jingoism. None, and it would be incredibly difficult for the media to trot that term out for nationalists. The other major difference from 19th century nationalism and today is that it is not simply English nationalism vs. French nationalism vs. Polish nationalism. These nationalist movements are not in competition, and if anything, see a fraternal connection between each other because they are all fighting the empire. That is not due to Russian money connecting them all, but the reaction by the community minded in response to the "McWorld" globalism shoved down their throats.
Now the Brexit vote may shift decision making to a body run by the anglo trained elite from a continental domiciled anglo trained elite, but goddammit, it's their bums making decisions. Cameron and his ilk are discredited. Cameronism is dead. The GOP as it stands now will not be the same next year or next decade as it looks today, but it will not mimic what David Cameron tried across the pond.