Mitt Romney launched an aggressive counteroffensive this week intended to cut into one of President Obama's biggest advantages in the presidential race: Voters like him.

Polls showing Obama with a consistent edge in "likability" over the stiffer Romney have worried Republicans.

Romney's aides said his comments that Obama should take his "campaign of division and anger and hate back to Chicago" reflect real anger with the tone of the president's campaign, but they acknowledged the counterattack is also strategic.

They said internal campaign polling and focus groups show the GOP attacks on Obama's rhetoric and campaign ads are lowering Obama's favorability numbers.

"We're seeing that the president's outrageous attacks are beginning to take a toll on his image," a senior Romney adviser said. "Keep in mind we're only in August. These kind of attacks are not going to wear well with voters, especially given the image that the president has built up as someone who's supposed to transcend politics as usual."