California has a reputation for progressive reforms in areas ranging from safeguarding its pristine coastline to protecting vulnerable undocumented immigrants. But some of the state’s reforms have yielded harmful consequences. One example is the way unusual way California chooses its primary nominees.

California’s “top two” primary system is not only confusing but harmful. It has denied voters access to choices fundamentally necessary to guarantee a representative democracy. The reformed system has crippled the electorate’s ability to nominate candidates from all political parties, which are often critical to helping voters understand key differences in political philosophy as expressed through candidates.

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The problem exists because of Proposition 14, the “Top Two Primaries Act,” which was passed by voters in 2010. The initiative provided that the two candidates with the largest numbers of votes in a partisan primary would face off in the November general election irrespective of the candidates’ political party memberships. The proposal was based on the belief that the new system would encourage candidates closer to the center of the political spectrum, given that only two slots would be available in the fall election. This, in turn, would lead to more moderate politics. Democrats have thrived during this period. However, no such moderation among the state’s Democratic legislators has occurred, although the connections between the voters and political parties have been weakened considerably.

Since 2010, the overwhelmingly liberal Democratic legislature has passed laws that permitted terminally ill people to end their lives; renewed cap-and-trade anti-pollution rules, enabled equal pay guarantees in the private sector; tightened gun controls; and enacted one of the highest minimum wage laws in the nation. The state has been dominated by a Democratic Legislature often capable of overcoming an onerous two-thirds vote requirement without the need to rely on a single Republican.

While moderation has eluded the hopes of “top two” reformers, many one-party districts have emerged. Since 2012, the first election year after the 2010 reforms, there have been sizable numbers of 20 state Senate and 80 Assembly districts where either Democrats face Democrats or Republicans face Republicans. Voters in those districts have been left without the November general election opportunity to vote for a candidate from the state’s two major parties or, for that matter, someone from a minor party.

In the three state legislative elections between 2012 and 2016, an average of 19 percent of the time voters were left only with intra-party choices in the fall. The trend continued in the June 5 primary, when the results left 16 intra-party contests awaiting voters this coming fall.

Much of the state has been relegated to one-party politics, hardly the hallmark of a representative democracy. Not only are one of the two largest parties left out of the final election, but the many colorful “third parties”—often the bellwethers of public angst—have been left on the sidelines as well.

There is nothing wrong with attempting to improve the sacred political process, whether in elections or other aspects of governance. There is something wrong, however, when reform does more harm than good. The “Top Two” system has not lived up to its billing. The state has been left with one-party government on the one hand, and a lessened opportunity to change it on the other. It’s time to return to the former system where all political parties are represented on the November ballot, and where the voters have choices among the full panoply of candidates. That system is much more likely to provide the kind of accountability the voters deserve.

Larry N. Gerston is political science professor emeritus at San Jose State University and author of “Not So Golden After All: The Rise and Fall of California.”