Depends on the economy come fall 2012. McCain still had a miniscule shot until Lehman.
People's attutudes about the economy usually solidfy by June of an election year.
That may have been right 4 years ago, but in this ADD, 24 hour internet news cycle - Voters want action today. Most people are connected to the Internet and are fed up with Obama. The key for every Republican, right now, is to announce for the Presidency, and get Citizens thinking about the election as if it were 6 months from now in November 2011. Increase the focus on Obama, increase the pressure and anxiety, because waiting until June of 2012 to hammer Obama will be too late. Most Citizens will be closely following the news in January for Iowa, NH, and South Carolina. The marketing themes established from November to February will plant the seeds for a Romney/GOP victory.