@ NYTimes.com, March 24 Does Joe Biden’s victory in 2020 represent the last gasp of an exhausted moderate tradition or does a potentially powerful center lie dormant in our embattled political system? Morris Fiorina, a political scientist at Stanford, argues in a series of essays and a book, “Unstable Majorities,” that it is the structure of the two-party system that prevents the center — the moderate majority of American voters — from asserting their dominion over national politics: Given multiple dimensions of political conflict — economic, cultural, international — it is simply impossible for two internally homogeneous parties to represent the variety of viewpoints present in a large heterogeneous democracy.