Recent political events have forced an examination of ideologies of populism and nationalism in politics. In this piece, I examine literature on the post-2016 political context to illustrate why the rise of identity-based politics has surprised analysts. An understanding of identity-based parties requires a focus on both the forms by which they navigate electoral and party systems, and the content of their rhetorical appeals to publics. I consider the electoral and party systems literature, and indicate some reasons that majoritarian electoral systems are more likely to foster the dominance of identity-based politics. In such systems, large parties might become weaponized by extremist elements, and lack the potential for checks from new parties. In addition, presidential systems lack a mechanism for no confidence votes, and might also have weak checks on an extremist executive. In terms of content, populism and nationalism might draw differing boundaries to include or exclude perceived elites. However, they can otherwise align in terms of their stances against “Others,” and against individualistic or technocratic stances that may fall under the label of “liberalism.” Nationalism and populism are not simply ideologies, but can be used as strategies by elites who can successfully deploy these mobilizing rhetorical appeals.