The Wall Street Journal highlighted research by Christian Grose of the USC Dornsife College into an association between top-two primaries and more moderate candidates.
TOP-TWO PRIMARIES in congressional elections, in which candidates of all parties run in the same primary and then the top two finishers face off in a second round, are associated with more moderate legislators, according to new research by University of Southern California political scientist Christian Grose. Open primaries, in which voters of any party registration can vote in a party primary, also reduce ideological extremity, though to a lesser degree than the top-two scheme. Just three states—California, Louisiana and Washington—used the top-two system in 2020, but Grose suggests "that those in the policy community looking for ways to reduce ideological extremity among legislators" should consider them.