I would support Santorum over Rubio.
I saw Rubio in an interview where he said that we were looking at many people outside the United States as "statistics", and that there are many people who would like to come here to work. It's true that there are many people who'd like to come to America to work, but if they don't understand how our form of government allows for such a desirable working environment, then they'll vote it away when they get here.
I think Hispanics who complain about White Americans' concerns over changing demographics are dishonest, and I think they know full-well that as the Hispanic demographic in America increases, so does the set of Hispanic cultural values that have turned Mexico, Cuba, Venezuela, etc. into places where no one wants to live.