In a couple weeks, California will hold yet another general election with third parties being mostly kept off the ballot, Republicans being under-represented on it, and Democrats having to spend millions in contests against other Democrats.  I wanted to share a way that it could be worse.

In St. Louis, voters are looking at a ballot measure called “St. Louis Approves.” Proposition D threatens to dilute the political power of the city’s substantial African American population, limit voter choice for everyone, install an untested voting method likely to fuel strategic voting, and shut out minority voices. Here’s an early warning to keep this proposal out of California.

Proposition D would make three major changes to St. Louis elections.

First, it replaces the partisan ballot used in state, congressional, and presidential elections with a nonpartisan ballot. Not allowing voters to see candidates’ party affiliation undercuts accountability and transparency.

Second, each party would no longer nominate their own candidates before an election among independents and the party nominees. Now the final election will only have the two candidates with the most votes in the primary, shutting out everyone else. Even if that’s the norm now in California, it would be new to St. Louis.

Third, adding fuel to the fire, the primary would replace a one-person, one-vote system with a so-called “approval voting” ballot. Some voters might use three votes and others just one vote. A candidate could fail to advance from the primary even if the first choice of more than half the voters.

To be transparent, I have always opposed the “Top Two” primary. I believe general elections should have a full array of choices – not just Democrats and Republicans, but third parties and independents who can enrich the conversation and inspire more participation.

While my legal efforts to block the California law failed, my fears have been realized. Today, third parties in California rarely make the general election ballot. When a November election is between two candidates of the same party, many voters just skip the contest. It now costs much more to run, especially when two candidates from the same party compete against one another in November.

California’s shortcomings will be multiplied with this approval voting experiment. We already know of approval voting’s troubled record when tried in organizations and college campuses. The largest association with it, the Institute of Electrical and Electronics Engineers, dropped it. Dartmouth College alumni repealed it by a vote of 81% to 19% after two controversial outcomes where “stealth” candidates won. Princeton and Dartmouth students recently repealed it; the remaining two campuses with it show rampant strategic voting.

In most of these experiments, the elections have been with one winner. That means most voters cast just one vote, like in traditional elections. Proposition D, however, would install approval voting to advance two candidates. That opens the door to a range of tactics. For example, well-organized voters will seek “approve” of two candidates only and hope less organized voters throw some votes their way. Even if in the minority, both candidates might capture both spots for the general election.

This is dangerous in diverse places like California and St. Louis.  Although the Democratic primary electorate has a strong African American majority, the African American share of the overall population is under 50 percent. If there is an organized effort by White voters to support just two candidates, a slim majority in the primary could seize control of the general election ballot.

What’s worse is that voter turnout will be especially low in the primary. St. Louis elects its mayor and other city offices in the spring of odd years, making turnout already low. It will be even lower in primary contests that no one wins, but just earns the right to advance. Expect primary turnout to be barely half of general election turnout.

This is a recipe for well organized, higher-income, older voters winning both primary slots. Younger, less White, and less wealthy voters could be shut out.

I’m no defender of the status quo. I’ve supported voting rights changes like automatic voter registration and Ranked Choice Voting for decades. But this scheme should stay in the laboratory: it’s worse for racial fairness, voter choice, and majority rule. Let’s keep it out of California — and hope St. Louis voters reject it this November.