"Anyone but Romney": 52%
Although Romney's victory is significant in percentage terms, the voter turnout for the caucuses was not substantial.... not much enthusiasm evident from GOP electorate.
FYI: same story in Florida:
2008 GOP primary turnout: 1.95Mn... turnout down ~15% from 2008... and this in a year when anti-Obama sentiment OUGHT to be driving GOP enthusiasm!
2012 GOP primary turnout: 1.66Mn