It looks like concern within Mitt Romney’s campaign that the prolonged Republican presidential primary could damage his standing among undecided voters has some legitimacy.

A new USA Today/Gallup poll gauging support among independents in swing states finds that President Obama holds a 48% to 39% advantage over the presumptive GOP nominee Romney, a significant change from polling conducted last year.

The poll, conducted before Romney’s primary victories on Tuesday, also places Obama’s overall support in 12 swing states above Romney’s, 51% to 42%.