politicalticker.blogs.cnn.com — (CNN) - Republican Sen. Marco Rubio, who consistently makes the short list of potential GOP vice-presidential candidates, on Sunday offered a ringing endorsement of Jeb Bush for the No.2 spot. Bush, the former Florida governor, recently said he hoped Rubio would accept a potential offer from presumptive Republican presidential nominee Mitt Romney to serve on the ticket, and Rubio returned the compliment.