The United States House of Representatives has 435 voting members. In 291 of the districts (66.9% of the districts), independent voters can vote in all major party congressional primaries, without having to join any party. In another 20 districts, independent voters can vote in any major primary but they must join that party at the polls on primary day. In another 7 districts, independents can vote in Democratic primaries without joining the Democratic Party, but they can’t vote in Republican primaries.
States in which independent voters can’t vote in either major party’s congressional primary without joining a party have 137 districts out of the 435.
The reason this data is worth mentioning is that many proponents of top-two primaries repeatedly publish misinformation. For example, John Opdycke, President of OpenPrimaries, has this op-ed in The Hill of July 7. The op-ed says “most congressional representatives are elected via an electoral system that empowers the few and excludes the many.”
The op-ed also implies that “the vast majority” of voters are excluded from major party congressional primaries. Actually, 73.3% of U.S. voters in the states with registration by party are registered members of parties; 26.7% are registered as independents, or as members of unqualified parties.
Finally, the op-ed says the California top-two system caused an end to late budgets. Actually California’s legislature was able to pass state budgets on time after 2010 because in November 2010, California voters passed Proposition 25, which eliminated the requirement that the budget pass with a two-thirds vote in each house of the state legislature. Once that happened, it was easy for the Democratic majority in each house to pass the budget favored by the Democratic legislators. The top-two system had no impact on whether the budget passed on time.
