HARRISBURG, Pa. (AP) — The TV screens of Pennsylvanians are suddenly empty of presidential campaign advertising as the post-Labor Day campaign season begins.

An independent media tracker and various independent advocacy groups said Wednesday that no ads are running in Pennsylvania, which traditionally has been treated as an important swing state in presidential elections.

But independent polls over the summer have consistently shown President Barack Obama, a Democrat, with a lead over his Republican challenger, former Massachusetts Gov. Mitt Romney.

Since mid-April, the Obama campaign and advocacy groups have spent millions of dollars on ads. Romney’s campaign last advertised on TV in Pennsylvania in April.

A spokesman for Crossroads GPS, a group associated with Republican strategist Karl Rove, insists Pennsylvania is still competitive and that the group may advertise in the state again.

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