Henry Olsen of the National Review: Romney highly unlikely to win

http://www.nationalreview.com/blogs/print/332590

Key quotes:

"You again see remarkable similarity. If you average these together, you get a rough estimate of 74 percent white, 26 percent non-white. This is identical to the 74–26 breakdown in 2008, and much more non-white than the 76–24 breakdown in 2010." (emphasis mine)

"Romney cannot win the popular vote unless he takes a minimum of 58.66 percent of the white vote and 20 percent of the non-white vote and whites are 74 percent of the electorate. His chances for victory increase the higher the share whites are in the electorate, such that at the 76 percent level, Romney wins the popular vote if he takes 58.66 percent of the white vote, so long as he takes 18 percent of the non-white vote"

Conservatives who actually look at data (see my earlier thread on the Washington Examiner's Tim Carney) are not optimistic.