In May, the Obama campaign devoted $25 million to campaign ads, most of it to a slew of positive spots highlighting his record on issues from health care to the auto-bailout. One featured an Ohio autoworker hailing Obama for “sticking his neck out” for the industry. In another, Obama explains why he decided to bail out the car companies. A third is simply an animated chart showing job growth under Obama’s tenure in office, ending with a text overlay “Do we really want to reverse course now?”

The investment has not paid off, by the standard measure of ads’ effectiveness, polling. While Mitt Romney’s numbers jumped in May — largely the result of him solidifying support among Republicans after the primary — Obama’s numbers barely moved in some surveys; in others, they went down. Obama averaged a 47-percent job approval rating in May — the same as in April — according to Gallup surveys. In a head-to-head with Romney nationally Obama’s numbers remained within the margin of error. And in a series of swing states like Iowa, Wisconsin, and Colorado, Obama ceded ground to Romney. The Republican candidate also pulled even with Obama in swing states like Nevada, Colorado, and Iowa in the latest NBC News/Marist poll.

The recent polls “would suggest that the [Obama] ads had no effect or the opposite effect,” said Republican pollster Whit Ayers.