Crossover Votes Not Talked About?

Lex mentioned a week or so ago that he was holding  his nose and voting for Obama to do his part to keep Hillary out of the White House.  I did the same thing here in Wisconsin and so did my wife via absentee ballot.  I don’t see anyone speaking in the major media about the fact that Obama must be getting thousands and thousands of votes from those crossing over to vote for him in the primary contests.  Am I the only one that has not seen anyone talking about this?