By Larry Kane

PHILADELPHIA (CBS) — Some key indicators on the upcoming presidential election show a very tight race that may be slowly moving toward re-election for President Obama.

With Mitt Romney on the defensive, a new trio of state polls shows how serious the challenge might be for him in the coming weeks.

quinnipiac poll x New Poll Shows Obama Strengthening in Three Key StatesThe CBS News-Quinnipiac University survey shows, first, that Romney’s gamble on Paul Ryan delivering his home state of Wisconsin is not working yet. Obama is at 51 percent approval rating in that state, Romney at 45 percent.

In Virginia, Obama is at 50 percent, Romney at 46. And in Colorado, after holding a five-point lead in August, Romney has lost the lead. It’s now Obama 48, Romney 47.

kane larry tight New Poll Shows Obama Strengthening in Three Key States

(KYW’s Larry Kane)

The electoral votes decide this election, and it could come down to a single state. Observers are saying that Pennsylvania is no longer a “swing” state, with Obama holding a six-point lead over Romney.

The latest three state polls were taken after the events in Libya that included the death of our ambassador, and before the release of the tape in which Romney declares that he has written off the votes of 47 percent of Americans whom he says are overly dependent on the government and therefore support Obama.

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