Reid Wilson, The Hill–

Democratic strategists fear a pending catastrophe in California, where so many Democrats are running for Republican-held House seats that they’re threatening to box the party out of general election races.

Now Democrats are spending precious resources to boost turnout, hoping that their embarrassment of candidates does not turn out to be a straight-up embarrassment. Party leaders have dropped millions of dollars into key GOP-held districts in Southern California.

California’s primary system will send each race’s top two vote-getters, regardless of party, on to November’s general elections. Democrats fear their plethora of candidates may so divide their voters that they get shut out of several winnable races, while Republican candidates facing less divided fields advance.

If that happens in any of those prime districts, Democrats will have only themselves – and the Supreme Court – to blame.

In 1996, California voters opted to hold an open, or blanket, primary. That system allowed a voter to pick nominees of different parties for different races – so a voter might pick a Republican in a Senate race, a Democrat in the race for governor and a Libertarian in the race for Congress.

The major political parties hated the idea. They argued that parties had the right to control who picked their nominees; only Democrats should get to vote in the Democratic primary, and only Republicans should be allowed to vote on the GOP field. The blanket primary, they said, robbed them of that right by opening nominating contests to voters of any political persuasion.

In 2000, the Supreme Court agreed. In California Democratic Party v. Jones, Justice Antonin Scalia, writing for a seven-justice majority, ruled that blanket primaries in California, Washington and Alaska did in fact violate a party’s First Amendment right of association.

Voters who had grown used to hopping between parties on a primary ballot weren’t happy with a closed primary system that forced them to choose one side or the other.

Washington state, which had created its blanket primary back in 1935, was the first to try a workaround. In 2004, voters passed a ballot initiative creating the top-two system, one designed to avoid the question of nominating candidates altogether.

Again, Washington’s political parties sued. Democratic lawyer David McDonald – a member of the Democratic National Committee’s Rules and Bylaws Committee – and Republican lawyer John White put aside their party difference to argue that the state had no compelling reason to regulate the way either side picked its nominees.

“I don’t think that wanting to determine who and how your nominee is selected is really an extraordinary notion,” White said at the time. “The ability of a political party to select its message and messengers is really what a political party is all about.”

This time, in Washington State Grange v. Washington State Republican Party, the Supreme Court disagreed.

Another 7-2 opinion in 2008, written by Justice Clarence Thomas, held that the top-two primary system was perfectly constitutional because the primary did not actually choose specific party nominees. (Scalia dissented, again citing the right of association.)

Two years later, California voters bucked party leaders again and implemented their own top-two system.

In the years since, both Democrats and Republicans have missed out on general election slots because their primary electorates were divided among multiple candidates. Rep. Steve Knight (R) won his seat in 2014 against a fellow Republican after Democrats finished third and fourth in the primary. In 2016, Sen. Kamala Harris (D) won her seat against a fellow Democrat after Republicans failed to field a top-tier candidate.

Had the blanket primary gone unchallenged so many years ago, Knight would have faced a Democrat, and Harris a Republican, in their respective general elections. This year, Democrats risk missing out on several districts – including Knight’s – if their candidates divide voters in too many factions to reach the top two.