Many on the right have had heated debates about whether a third party is a viable option for conservatism. They probably didn’t expect the third party to be the GOP.

Despite giving us Ronald Reagan, California hasn’t exactly been a beacon of conservatism for the country but outside the major urban centers you could usually find some pockets of strong Republican support. That might be changing as the number of registered Republican voters in the Golden State has finally fallen behind the unaffiliated.

The California Republican Party is now outnumbered by independent voters by 73,000, according to Political Data Inc., which tabulates voter file data from county registrars.

The new figures come as the state looms large in the national battle for the House, with a handful of Republican-held seats poised to play a pivotal role in November.

Among California’s 19 million registered voters, the latest statistics — as of 15 days before the June 5 primary — show that Democrats now make up 8.4 million or 44.6 percent of the electorate.

That compares with 4,844,803 no-party-preference voters, or 25.5 percent of the state’s voters and 4,771,984 Republicans, who both make up about 25.1 percent. The California Secretary of State’s office is expected to release its own official count later this week.

One analyst says it’s too soon to determine whether this is a real indicator of voter preferences because California’s voter registration process separates registration from picking a party affiliation. If that were the whole reason one would think Democrats would be affected similarly but that doesn’t seem to be happening.

Democratic numbers have also declined, though not nearly as dramatically — the party made up 46.8 percent of the voter rolls a decade ago. By contrast, the percentage of “no party preference” voters in the state has more than doubled in the past two decades, the latest data showed.

Political analyst Carson Bruno, now a dean at Pepperdine University, cautioned on Twitter that it’s still unclear “how much of the NPP gain is due to the implementation of automatic voter registration,’’ which auto-registers new voters as NPP and requires them to select a party later.

Naturally the GOP has happy words to spin the development but

And Matt Fleming, spokesman for the California Republican Party, downplayed the development.

“This isn’t surprising. Voters have been becoming more and more independent for years,” he said in an email statement. “But no party preference doesn’t mean voters are becoming Democrats, and we will continue to reach out to all voters. The rise in NPP suggests that voters are fed up with the status quo in California, which, by any objective measure, is Democrat control of Sacramento.”

Hoover Institution fellow Bill Whalen, an adviser to former Republican Gov. Pete Wilson, says GOP’s new third-party status can no longer be blamed on the passage of Prop. 187, the 1994 anti-illegal immigration ballot measure which had Wilson’s support and has long been tagged as a catalyst in the GOP free fall in California.

“You can only blame 187 for so long,’’ he said, adding that legions of new voters have since registered NPP as the viability of the GOP brand has collapsed in the state.

A declining GOP in a state governed by Jerry Brown shouldn’t be a surprise to anyone, I suppose. One has to wonder if the strident brand of populism which has infected the Republican Party is a factor. I think it would be unwise to dismiss the possibility.