Would the formation of Israel be an expression of nationalism? Can it in that light be seen as the belief that one's country or ethnic group is just as deserving as others'? Or to take a more recent example of Kurdish nationalism.
Trump’s campaign rhetoric is emblematic of nationalist themes. Anti immigrant. Playing up cultural mythos. Bragging about military capabilities. Blaming foreign nations for most problems. Implying that a return to core values will bring greatness. Lots of fear and anger.
Tends to be very effective for groups of people that used to be powerful but are no longer.