Mitt Romney’s decision to pick Paul Ryan as his running mate may not have given him a boost in national polls, but it is paying dividends in Ryan’s native Wisconsin. According to a new Public Policy Polling survey, Romney now leads President Barack Obama in Wisconsin by a 48 to 47 percent margin, representing a seven point shift from PPP’s last poll in July (which showed Obama leading 50-44.)

Although Wisconsin voters have a mixed opinion of Ryan — 49 percent view him favorably compared to 45 percent who view him negatively — the congressman is still more popular in the state than Romney (who has a 45/48 favorability rating,) Obama (46/50,) or Vice President Joe Biden (41/48.)

Ryan’s most tangible impact appears to be uniting Republicans behind Romney. In PPP’s last poll, Republicans supported Romney by and 87 to 9 percent margin; that lead is now up to 93 to 5 percent.

Obama is still ahead among independents, but his 47 to 43 percent lead significantly down from the 53 to 39 percent lead that he held six weeks ago.

Although Wisconsin has been a blue state in every presidential election since 1984, there is good reason to believe that it will be a swing state in 2012. The new PPP survey finds an electorate that’s 34 percent Republican and 32 percent Democratic; this represents a dramatic shift from 2008, when the electorate was 39 percent Democratic and 33 percent Republican. Furthermore, the state GOP is well organized and energized after successfully fighting off a recall challenge against Governor Scott Walker in June.

The Badger State would be a crucial pickup for Romney and the Republicans, as the state’s 10 electoral votes would help make up for potential losses in Western states like Nevada and Colorado, where Romney is expected to struggle among Latino voters.

Romney may not ultimately be able to turn Wisconsin red, but with Ryan on the ticket it seems clear that the state will truly be in play for the first time in years.