Fifty-seven percent of union workers who are registered to vote said they'd back Obama while 35 percent said they'd vote for Romney, the presumptive Republican presidential nominee, results released Monday indicated.
Non-union workers say they favor Romney over Obama, 48 percent to 44 percent, results indicated.
About 12 percent of workers who are registered voters interviewed April 11-June 5 for Gallup's Daily tracking survey say they are union members.
State government union workers are slightly more likely to support Obama than other government union workers, the Princeton, N.J., polling agency said. However, about three in 10 state workers who are union members and are registered to vote said they support Romney.
Results are based on nationwide telephone interviews conducted as part of Gallup Daily tracking survey with 13,376 employed adult registered voters April 11-June 5. The total sample's margin of error is 1 percentage point.
Results based on the sample of 1,643 employed registered voters who are union members have a margin of error is 4 percentage points. Results based on the sample of 813 employed registered voters who are union members and who work for the government have a margin of error of 4 percentage points.