Immigration is once again at front of Americans' minds with new Gallup polling showing a spike in those saying it is the "most important issue" facing the country.  And that spike was led by border states.

Fully 28 percent of respondents in these states (Arizona, California, New Mexico and Texas) said immigration was the nation's top issue, up from just 10 percent in June according to regional breakdowns provided to the Washington Post. Concern jumped by a smaller 10 points in non-border states, from 4 to 14 percent naming it as the nation's top issue. (Poll methodology below.)

Concern about immigration seems likely to continue to rise -- the Gallup poll was completed last Thursday, but news coverage of how the government will deal with over 68,000 unaccompanied immigrant minors has only intensified since then.

While Americans in border states are far more concerned about immigration, they are not more downbeat about President Obama's performance. A Washington Post-ABC News poll this week finds 41 percent of residents in the four border states approve of Obama's handling of undocumented immigrants, nine points higher than among poll respondents living in non-border states (32 percent). In both border and non-border states, big majorities disapprove of the way Republicans in Congress are handling the issue of undocumented immigrants in both border states (69 percent) and non-border states (65 percent).

Small majorities in both border and non-border states support a $3.7 billion proposal by Obama to speed up deportation hearings and provide care for unaccompanied children while they wait. Border-state residents support the idea by 56 to 41 percent, while those living in other states back it by 52 to 44 percent.

The Post-ABC poll was conducted July 9 to 13 among a random national sample of 1,016 U.S. adults interviewed on conventional and cellular telephones. The margin of sampling error for overall results is 3.5 percentage points. The error margin is 8.5 points among the 174 respondents living in states along the U.S.-Mexico border (Arizona, California, New Mexico and Texas), and four points among the 842 respondents living in other states.

The Gallup poll was conducted July 7-10, 2014 among a random national sample of 1,013 adults on conventional and cellular phones, carrying an overall margin of sampling error of plus or minus four percentage points. The July and June polls interviewed 206 respondents in border states in both their June and July surveys, equating to an error margin of plus or minus 8 to 9 percentage points. In non-border states Gallup interviewed 807 residents in non-border states and 821 in border states, equating to error margins of 8 to 9 points.

Peyton M. Craighill contributed to this report.