President Obama's job approval rating from Hispanics has slipped below 50 percent for the first time, according to Gallup's latest poll, an ominous sign for the president as he heads into campaign season.

Just 48 percent of Hispanics approve of the job Obama has done, while 37 percent disapprove. This is down from a 60 percent approval rating as recently as January, an erosion that came later than his slipping numbers with Anglo voters. This trend should worry Obama: Hispanics are the largest and fastest-growing minority group in the country, and there are high numbers of Hispanic voters in swing states including New Mexico, Florida, Colorado, Nevada and even Virginia.

Obama has backtracked away from a campaign pledge to overhaul the nation's immigration laws, but the economy might be taking a larger toll on his Hispanic support.

Hispanic workers are disproportionately represented in the construction and manufacturing industries, which were mortally wounded by the 2008 recession and have shown little recovery. The national unemployment rate for Hispanics was 11.3 percent in August, 3.3 percentage points higher than the national average for non-Hispanic whites.

Obama's drooping August numbers were not confined to just Hispanics. Just 33 percent of non-Hispanic whites approve of the job he is doing, a new low for the president, while among African-Americans his support is down to 84 percent, which ties for the lowest of his presidency. Overall, Obama's job approval rating is down to 41 percent from 44 percent in July.