The figures from the USC Dornsife/Los Angeles Times "Daybreak" tracking poll of the election provide additional insight into how opposition to immigration in general – not just the illegal variety – has helped fuel the political movement backing Trump.
Told that the U.S. gives immigration visas to about 1 million people each year, just over half of Americans in the poll said that the number is either "about the right" amount or is too small.
Hillary Clinton leads Trump as the preferred presidential candidate among those who gave either of those responses.
Trump, by contrast, got the support of six in 10 who said that the current level of legal immigration is too high. Those holding that view make up the largest share of Trump's backers.
Although combating illegal immigration has been a major focus of Trump's campaign, he has also embraced plans to significantly cut back on legal immigration.
In a speech on immigration policy he gave in August in which he described his plans in detail, Trump endorsed a proposal to cut back on all forms of immigration until the share of the U.S. population that is foreign-born returns to its "historic norms." Achieving that goal would require a drastic reduction in legal immigration for decades.
That position squares with the views of Trump's supporters, who were also much more likely than those backing Clinton to say that legal immigration has had a negative impact on the country.
Presented with several statements about "people who are granted immigration visas to come to the U.S. to work and live," about one in five said that those immigrants "harm the American way of life."
Roughly three in 10 said that legal immigrants "come to the U.S. because they want a handout" or "increase crime in American cities." Four in 10 said that immigrants "take jobs away from Americans."
Trump led Clinton by between 2-to-1 and 3-to-1 among the groups holding each of those positions. By contrast, Clinton led among each of the groups that chose positive depictions of immigrants: that they come to the U.S. to work, that they provide welcome variety to U.S. life, that they strengthen the economy and that they revitalize U.S. cities.
The Daybreak poll asks a series of questions to a panel of 3,000 American adults each week. Questions regarding which candidate respondents intend to support are asked each week. Additional questions on issues are rotated into the poll periodically. The immigration questions were asked starting in mid-September.
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