Is it possible for nationalism to avoid being based on either race or ethnicity?

It seems, on the surface at least, that for the most part nationalism has a strong focus on exclusion based on ethnicity or race by very often aiming to protect the nation from foreigners, with foreigners being mostly identified by the different biological appearance (race) or their different customs (ethnicity). However, this essay shows that neither ethnicity or race are the driving force behind nationalism but that nationalism and ethnicity are vulnerable to political exploitation and therefore often appear to go hand in hand.