California, the largest of America’s fifty states, is normally an afterthought in presidential politics. It is reliably Democratic in the general election and comes last in the primaries, meaning that by the time Californians vote both parties have usually found their nominees.

This year could be different.

If Donald Trump continues on the path he’s on, California’s 172 Republican delegates could make or break his presidential aspirations.

The Manhattan businessman has so far secured 950 of the 1,237 delegates he needs to win the nomination outright. If he falls short of a majority before the delegates convene in Cleveland, Ohio this summer, the party could nominate someone else instead on a second or third ballot when most delegates will be unbound.

Moving target

FiveThirtyEight calculates that Trump is 97 percent on target to get the 1,237. He underperformed in March and early April but has since won his home state of New York and five more Northeastern contests.

The Indiana primary next week could be something of a last stand for his main rival, Texas senator Ted Cruz. If Trump were to prevail in Indiana — a demographically diverse state with 57 delegates — stopping him would become very difficult.

But if Cruz makes a dent in Trump’s delegate count in Indiana, the contest could go all the way to California.

And what will happen there is anyone’s guess.

Fickle

The RealClearPolitics average of polls puts Trump ahead in the Golden State with north of 40 percent support.

But surveys have been volatile. Trump’s lead has been anywhere between 27 and just 1 percentage points. One poll earlier this year even put Cruz ahead.

It may be that California’s Republicans are fickle. More likely, pollsters are having a hard time figuring out who actually will vote.

Companies have decades of experience polling primary voters in states like Iowa and New Hampshire, which vote first. Because California is usually of no consequence in the nominating contest, they aren’t very expert in reading its primary electorate.

Outsized influence

Even if they were, statewide polls would be of little use because voters are so unevenly distributed across the state.

In 2008, nearly half a million people turned out in the Republican primary in Los Angeles. Another 300,000 voted in San Diego County. In Modoc County in the far north of the state, by contrast, and Imperial County in the far south, only 1,710 and 4,234 people voted, respectively.

Yet those lightly-populated areas have outsized influence in the presidential contest because California allocates the majority of its delegates according to the outcome in each of its 53 congressional districts. Whoever wins the most votes in a district receives all three of its delegates.

It’s a rule that could benefit Trump this year. He has seldom won majorities anywhere but prevails when the opposition against him is divided.

California awards another thirteen delegates to the statewide victor; another rule that could help Trump, whatever his laments about the nominating contest being “rigged” against an outsider like him.

“No earthly idea”

It’s hard to anticipate what will happen at the district level. As Sean Trende, an elections expert, puts it, “Who is voting in Nancy Pelosi’s district in a closed Republican primary? I have no earthly idea.”

One would suspect these are more socially liberal voters than the average Republican and hence should favor John Kasich, the relatively moderate governor of Ohio.

On the other hand, Trump has done well in majority-Democratic districts elsewhere: often with white working-class voters who are attracted to his combination of economic populism and political incorrectness.

Cruz may do better in the inland areas where his uncompromising brand of conservatism could resonate with rural and religious voters. But immigration is a key issue for many of these hard-right voters and that is Trump’s forte.