Riding a rebellion fueled by opposition to illegal immigration and pessimism about the nation's future,
Yet the party whose nomination he is seeking has fractured because of his candidacy, with ominous prospects for
A quarter of California Republican voters polled said they would refuse to vote for Trump in November if he is the party's nominee. Almost one-third of those backing Trump's leading competitor, Texas Sen.
That division sets up the potential of cascading losses down the ballot for Republicans already fighting the tide in one of the nation's most Democratic states, including in a number of contested congressional districts.
Trump, passionately supported and deeply reviled in different corners of the electorate, has extended his reach among Republicans since the last USC/Los Angeles Times poll was taken in September. He now has the support of 37% of GOP voters surveyed, up from 24%.
Cruz, who was in single digits in the last poll behind candidates who have since left the race, is now at 30%. The third candidate, Ohio Gov.
But among the voters most likely to turn out, the poll shows the race between Trump and Cruz is nearly tied, with Trump at 36% versus Cruz at 35%. The difference illustrates how a low turnout in the June 7 primary could hurt Trump and boost Cruz.
How many Californians will turn out remains hard to predict because the state has not seen a fully contested June Republican primary since 1964. Also hard to predict is how the overall support for the top candidates will translate into delegates to the Republican nominating convention this summer. The state's GOP awards delegates to the winner of each congressional district, so a candidate could lose statewide but still pick up a significant number of delegates.
The poll shows Trump leading in most areas of the state except the Central Valley, where conservative voters put Cruz ahead. In Los Angeles County, the two are nearly tied.
But the controversial Trump clearly has commanded wide swaths of his party in California. The survey showed him leading among college graduates and those without college degrees, and among almost all ranges of income. There was no distinction between the level of support from men and women, despite Trump's well-publicized tirades against women like Fox News anchor Megyn Kelly.
His support draws on voters like Teresa Sumter, who lives in the Modesto suburbs.
"I don't believe the politicians anymore, and he's not really a politician," said Sumter, who is 60 and runs a surgical cleaning crew at a hospital. "I like what he says."
Sumter said she had never really cared for Trump before this campaign, figuring him as simply a "rich man." That has changed.
"He thinks like we do," she said, listing illegal immigration as one of her prime issues.
"He tells it like it is," she added. "I don't think he's lying to us."
Trump's views on immigration are one of the pillars of his candidacy, but the subject also accounts for a serious party fissure in California, where fallout from the 1994 fight over an anti-illegal-immigration measure has contributed greatly to the GOP's shrinking presence.
Among those in the poll who said illegal immigration was a "crisis" in California, Trump won 48% of the vote, to Cruz's 29% and Kasich's 8%. Among voters less concerned about illegal immigration, Trump's level of support fell to the point that he won only 27% of those who didn't consider it a problem.
About 3 in 5 Trump supporters polled felt illegal immigration was at crisis levels, and 90% described it as either a crisis or a major problem. That sets Trump's backers apart from California's voters as a whole, of whom only 23% said they saw a crisis. Among California's registered Republicans, 44% said they saw illegal immigration as a crisis.
Trump's backers also diverge from the rest of the state on the solutions they seek. Just over half of Trump voters polled said those in the country illegally should be deported, the position their candidate has espoused since he entered the race. An additional 28% of his supporters said those immigrants should have a path to citizenship, and 14% favored a narrower right to work legally in the U.S.
Among all Republicans in the poll, only a third backed deportations and 2 in 5 favored a path to citizenship.
Californians as a whole rejected deportations decisively, with only 16% backing that course and two-thirds favoring a right to citizenship for those currently living here illegally.
Only 3 in 5 Republicans said they agreed with Trump's views on immigration, which besides mass deportations include the construction of a giant wall along the nation's southern border. One in five Republicans said they strongly disagreed with his positions.
Similarly, among Trump voters, 69% approved of his proposal for a ban on travel to the U.S. by Muslims. That view was shared by only 44% of Republicans overall, and by only 22% of Californians polled. Even among supporters of Cruz, who has suggested similar restrictions on Muslim travel, only 42% said they backed Trump's plans.
A starkly negative assessment of the economy and, more broadly, the future, also marked Trump voters.
Among those who think the nation's best years are behind it, Trump carried 40% of Republicans, to 26% for Cruz. Among those more optimistic about the country, the two were tied at 36%.
All told, only 13% of Trump voters felt that the state was headed in the right direction, whereas Californians overall were split. Cruz voters were similarly negative, but Kasich's supporters were more upbeat.
The impact of those views extended to a hypothetical general election matchup between Trump and Democratic front-runner
The breadth of Trump's success in California so far — he led almost all major GOP subgroups except for
"In some ways, it's as much stylistic as it is demographic," said Gutermuth, of the Republican polling firm American Viewpoint, which along with Democratic firm Greenberg Quinlan Rosner Research conducted the poll for the USC Dornsife College of Letters, Arts and Sciences and the Los Angeles Times.
When Republicans were asked what kind of presidential candidate they wanted, three categories explained the success of the antagonistic outsider profile that Trump has taken on.
One in five voters said their top priority was a candidate who would represent change; an additional 15% wanted one who would tell it like it is, and 11% wanted someone free of the influence of special interests. In those categories, Trump was far and away the leader. Among those who wanted a blunt-talking candidate, for example, Trump carried 64%, compared with 10% for Cruz and 9% for Kasich.
But Trump's attitude — and his denigration of Mexicans, Muslims, women, the disabled, even prisoners of war — has exacted a price that hurts him in a general election and may yet hobble him in the primary.
Overall, about three-quarters of California voters polled had an unfavorable view of Trump, an eye-opening level for a front-runner. Even among Republicans, only 51% had a favorable impression of Trump, while 43% had an unfavorable view.
And the unfavorable views were expressed with vehemence. Two-thirds of nonpartisan voters, who are essential to any chance of success for a member of the Republican minority in California, had a "very unfavorable" view of Trump. Seventy-seven percent of Latinos, 74% of those under age 50, 67% of women, 61% of men, and more than 3 in 5 voters of all education and income ranks had a very negative view of him.
"He's an egomaniac who does very stupid things," Barry Kolom, a Los Angeles optometrist, said of Trump. "He shoots from the hip; he has no filters. I just think he's a loose cannon."
Cruz, Kolom said, is "more consistently conservative" and is his default candidate against Trump.
"Unfortunately," he said, "a lot of people believe that if you are wealthy, you have to be smart, and that's definitely not the case.... Honestly, I think he's pathetic."
Views like that make Republican leaders shudder as they ponder the impact Trump's presence at the top of the ticket could have on down-ballot races. Those fears are real, according to the poll. Almost one-third of voters who described themselves as traditional Republicans said they would refuse to vote for Trump in November, as did 17% of tea party Republicans.
One in 5 Republicans said they would vote for Clinton over Trump in a general election matchup. Fewer would cross the aisle if Cruz or Kasich were nominated.
The poll contacted 1,503 registered voters in California between March 16 and March 23. The sampling error for all voters is 2.8 points in either direction; the margin of error for Republican voters is 5.5 points in either direction.