Here is a webpage showing numerous poll results over many years. It's highly informative.
Immigration
At a quick glance, the polls suggest, to me, exactly what I'd expect. Americans are not heartless; we don't want to "round 'em up." Americans are also fed up; we do want illegal immigration stopped.
In contrast to another member's claim that illegal immigration is an unimportant issue, a poll conducted between Nov. 30th and Dec. 3rd of last year shows 81% of Americans feel that illegal immigration is "Important" or "One of the most important" problems facing the country.