From Public Policy Polling:

PPP’s first Wisconsin poll since Mitt Romney announced Paul Ryan as his running mate finds him taking a small lead over Barack Obama in the state, 48-47. That represents a 7 point shift from PPP’s last look at the state in early July, which found Obama ahead 50-44.
The biggest change Ryan’s selection seems to have brought about is the unification of the GOP. Romney’s gone from a 78 point lead with Republicans on our last poll (87-9) to now an 88 point lead with them (93-5). There’s also been a tightening with independents. Obama still has a 4 point lead with them at 47-43, but that’s down from a 14 point advantage at 53-39 six weeks ago. Democrats are unchanged from the previous poll.

It’s been 28 years since Wisconsin voters chose the Republican presidential candidate — and the state wasn’t even among those considered by the Romney team back in May as part of the campaign’s efforts to get the 270 electoral votes.