The unexpected rise in inflation reported Tuesday was an unwelcome blow for U.S. President Joe Biden's Democrats, but a new Reuters/Ipsos poll shows Democratic voters are just as enthusiastic as their Republican counterparts, pointing to a potentially close contest in November's elections.

Republicans remain favored to win control of the U.S. House of Representatives — with the Senate on a knife-edge — amid widespread dissatisfaction with Biden's presidency and months of sharp price increases that the poll showed remain the top concern for Republican and Democratic voters alike.

Labor Department data showed consumer prices rose a tenth of a point in August, confounding analysts' expectations for a decrease. The rise was fueled by higher prices for food, rent and health care.