WASHINGTON -- From Dick Cheney to Hillary, political elites denounced Donald Trump's call last week to ban all Muslims from the United States in the wake of the San Bernardino shootings. Civil rights leaders called the idea "grotesque.''
But among largely white, working-class Americans, Trump's serial attacks on immigrants, starting from the moment he announced his candidacy in June by calling some Mexican immigrants rapists, have hit a rich vein of unease over record immigrant flows into the U.S. that have radically altered the nation's ethnic makeup and displaced native workers in industries from construction to meatpacking to high tech.
The anger is reminiscent of earlier backlashes during comparably large flows of new arrivals.
"Trump taps into that anxiety as someone who hears and understands, and isn't afraid to say out loud in the national media what many individuals think privately and discuss at home and in their churches and workplaces,'' said Mark Jones, a political scientist at Rice University's Baker Institute in Texas.
Decades of Gallup polls have shown a substantial portion of the public, at times large majorities, favoring reduced immigration -- a sentiment ignored by both parties. The GOP's business wing has pushed for more skilled and unskilled workers from overseas, mainly by lobbying for large expansions of various visa categories, while Democrats, aligned with minority voters, have sought easier entry for family-based migrants and legalization for those who entered the U.S. without permission, but have since established themselves.
But the San Bernardino shootings this month by a radicalized Muslim couple with roots in Pakistan, combined with several previous attacks in Boston, Fort Hood in Texas and elsewhere, has fused the immigration debate with terrorism.
Now, people are "looking at immigration not only through the lens of demographic change but also through the lens of national security and terrorism,'' Jones said.
The linkage of immigration with terrorism has magnified the political potency of both issues, Jones said. "That increases the level of resistance (to immigration) and the number of people who are aligned with Trump on this issue,'' he said.
In the past 50 years, a near-record surge of immigration -- much of it from Asia and Latin America -- has transformed the ethnic makeup of the U.S., reducing the white share of the population from 84 percent in 1965 to 62 percent today, with whites projected to drop into minority status by 2055, according to a recent report by the nonpartisan Pew Research Center.
The modern immigration wave has brought 59 million people to the United States, accounting for half the nation's population growth, Pew found. The research center projects that in the next 50 years, immigration will add another 103 million people to the U.S. population, bringing the total to 441 million, with immigration accounting for 88 percent of the growth.
"The racial mixture of our immigration stream has radically changed in the last 50 years, there's just no doubt about it,'' said Muzaffar Chishti, director of the nonpartisan Migration Policy Institute's office at New York University School of Law. ``We have also, in terms of pure numbers, beaten the old historic highs of the first decade of the 20th century.''
The political reaction to those immigration waves in the late 19th and early 20th centuries, which included large numbers of Italian and Polish migrants, was blunt, beginning with the Chinese Exclusion Act in 1882, the Asiatic Barred Zone in 1917 that blocked nearly all immigration from Asia and the Middle East, and the 1921 and 1924 national origin quotas that slashed overall admissions into the U.S. and heavily favored Northern Europeans.
A long immigration lull followed, until Congress made a U-turn with the 1965 Immigration Act, the least known of four landmark civil rights laws that its sponsors thought would preserve the nation's white majority while eliminating racially tinged national origin quotas that had become embarrassing at home and abroad.
"Guess what happened,'' Chishti said. "It flipped upside down.'' As Europe flourished, its citizens lost interest in leaving home. Instead, Asians and Latin Americans established family toeholds that grew rapidly into huge flows.
Today a similar dynamic appears to be under way with Middle Eastern and African migrants, many of whom arrive on student or work visas. Pew estimates that Muslims currently make up less than 1 percent of the adult U.S. population, but by 2050 will surpass American Jews in number. Pew estimates that 100,000 Muslims were granted permanent residency in 2012, about 10 percent of all new green card holders.
Simultaneously, various legal changes and economic forces contributed to a rise in unauthorized immigration from the 1980s to 2007, bringing to the U.S. an unauthorized population of 11.3 million. These immigrants began settling beyond the traditional gateway states of California, Texas and New York to the South and Midwest, the heart of Republican territory, where people had little prior exposure to large numbers of foreigners.
So, in addition to a "near record high population of foreign-born, we've also seen a dispersion of the immigrant population around the country,'' said Mark Hugo Lopez, Pew's director of Hispanic research. The large flows have "resulted in big and quick demographic changes in the racial and ethnic composition'' of the country, Lopez said.
A November survey by the nonpartisan Public Religion Research Institute found that 7 in 10 Trump supporters rate immigration as an issue critical to them personally, and 80 percent believe immigrants "are a burden on our country because they take our jobs, housing and health care.''
The poll found that 55 percent of Trump supporters are working-class whites, compared with 35 percent of those supporting other GOP candidates.
Wade Henderson, head of the Leadership Conference on Civil and Human Rights, said Trump is tapping "a wellspring of hatred that politicians have used historically. It combines people who are uncomfortable with demographic changes with people who have fears for their safety.''
Lina Baroudi, staff attorney for the Arab Resource and Organizing Center in San Francisco, agreed. "This is about racism and xenophobia,'' Baroudi said.
Others contend that Trump is exploiting legitimate concerns.
"The movers and shakers generally support a lot more immigration, whereas average folks are skeptical or want to rein that in,'' said Phillip Cafaro, a Colorado State University philosophy professor and author of ``How Many Is Too Many?'' in which he makes what he calls the progressive argument that high immigration has depressed blue-collar wages and set back environmental protection.
"Certainly a lot of things (Trump) says I find abhorrent, starting with the idea we won't let Muslims in because of their religion,'' Cafaro said. "But he's given people permission to talk about immigration and say what's on their mind, and elites do not like that.''
Whatever the case, simple arithmetic probably puts Trump on the losing side, immigration experts said, a prospect that has GOP officials at all levels in a state of panic. The share of Latino and Asian voters is "just going up,'' Chishti said. "That's an irreversible phenomenon.''