How did popular nationalism evolve in the last decades of the nineteenth century?

In the first two-thirds of the nineteenth century, nationalism convulsed the autocratic states of Europe. Liberal constitutionalists and radical republicans championed the national idea as a way to challenge authoritarian monarchs, liberate minority groups from imperial rule, and unify diverse territories into a single state. Yet in the decades after 1870 — corresponding to the rise of the responsive national state — nationalist ideology evolved in a different direction. Nationalism became increasingly populist and began to appeal more to those on the right wing of the political spectrum than the left. In these same years the “us-them” outlook associated with nationalism gained force, bolstered by modern scientific racism. Some fanatics and demagogic political leaders sought to build extreme nationalist movements by whipping up racist animosity toward imaginary enemies, especially Jews, and the growth of modern anti-Semitism after 1880 epitomized the most negative aspects of European nationalism before the First World War.