Idea for attack ads against Romney
Don't attack him. Give him a hug and a pat on the back.
Example: His campaign runs ads showing him in a positive light. "Romney supports X, because X is good for america."
Why not answer with an equally positive ad? Romney waving, Romney standing at a podium, a flag... and then a video-clip or quote: "Romney is against X, because X is bad for america."
Don't be mean. Don't be aggressive. A positive ad, with enough patriotism to make even a Teabagger scratch his head (think Colbert Report), maybe copying the style of the original ad, showing Romney proposing an idea/position totally contrary to what he is now running on.
"Let's kick out any illegal immigrants, even if they lived here for decades."
"Global warming is real."
"High gas prices are good."
Of course, that strategy depends on the assessments, that Romney's campaign will mainly run positive ads and that voters aren't actually stupid enough to mistake those "too-nice"-ads for being real.