http://news.yahoo.com/blogs/signal/romney-path-victory-goes-florida-ohio-virginia-172824466.html"If Romney can capture Florida, Virginia, and Ohio—the three swing states he's most likely to win—he will come within four votes of the magic number. At that point, he would need any one of the other swing states: New Hampshire and Iowa are the most likely, both near 55 percent for Obama. While Romney's running mate, Paul Ryan, hails from Wisconsin, the polls there have consistently favored Obama by about 4 percentage points. Data from the past 10 elections has demonstrated again and again that vice-presidential home state bumps are negligible."
Time will tell, but seems to me that choosing Ryan was a short-term tactical move (?) by Romney campaign to stop massive bleeding in national polls, and try and ride bump from VP pick and RNC convention to try and create some sort of superficial semblance of competitiveness in electoral college.