Obama also leads Gingrich and Santorum among Latinos who voted for John McCain in 2008. Overall, none of the four Republican candidates gets more than 14% of the Latino vote against Obama.
http://latino.foxnews.com/latino/politics/2012/03/05/gop-hopefuls-losing-ground-to-obama-among-latinos-poll-says/#ixzz1oGC8WunDNow, these numbers are on the high end of what we're seeing, and the poll itself notes that a quarter of Latinos might change their mind if there was a Latino VP nominee.
That said, George W. Bush made a more concerted effort to woo the Hispanic population than any previous Republican candidate had, and John McCain intermittently supported immigration reform. It wouldn't be surprising if Romney (or Santorum or Gingrich, for that matter), underperformed among Latinos relative to those two.
And if the Latino vote
were 85-15 for Obama, it would make a lot of states much harder for the Republican to win.
