I gather the strategy behind the ad is that Mitt Romney is the GOP's most formidable opponent for President Obama, and weakening him now could help one of the more vulnerable Republican candidates get the GOP nod, thereby improving Obama's reelection prospects. The strategy is a bit risky in any case. The GOP has other candidates who are electable in a declining economy, despite the clown show of recent months.
I confess that I'm a little curious about this. Are they really trying to rough up Romney enough that a patsy like Gingrich ends up with the nomination? Or are they doing it because they want to run against Romney and they know that attacks from Obama make him more credible in the eyes of the tea party? Or maybe because they think Romney is going to win the nomination regardless and they just want to set the narrative early?
This is mostly just idle curiosity on my part. I don't really care all that much, and the big picture is pretty simple: modern campaigns simply attack earlier and earlier every cycle. Still, I do wonder what the real strategy is here.