There is no real alternative to democracy in the modern world, and yet we all have seen democracies act in hateful and oppressive ways. In this middle ground, in loving and fearing democracy, republicans always face temptations on either side. If one contemplates too long the danger of democratic excess, of oppression of minorities in the name of an ethnic majority, then one might flee from ethnonationalism through republicanism all the way to minimalist liberalism. Under such circumstances, liberalism's siren call of a neutral and empty politics might prove irresistible. Conversely, if one contemplates too long the hollowness and hardheartedness of U.S. liberalism, one might begin to find attractive the kind of communal unity and support promised by ethnonationalism.
Republicans are always halfway down the slippery slope, scrabbling for a fixed handhold.
Otherwise, if groups of citizens have systematically different interests, then inevitably some will win and some will lose. We can have rule by men and by laws, because they are the same thing. In this regard, I think that historical republicanism shares much with some strains of ethnonationalism. Both prize unity and worry about difference. Both deplore change and wax nostalgic for a mythical golden age of simplicity.