He still has the luxury Romney and Co. lack in targeting a single opponent who cannot afford to ignore the others. The only danger is emphasizing differences with Romney increases the chance the GOP nominates its only credible candidate. Since they know he is the only credible candidate, too, that risk is small.

In a popular vote, I would call Obama the slight favorite, but I can think of few states except OH the past few months might have tipped from Romney to Obama. That jibes with Gallups end of January poll (which I realize was over a month ago) showing Obama exactly tied with Romney nationally but a point behind in swing states. That is still a statistical dead heat, but Obama does better nationally than in swing states, which must be troubling for his campaign.