I called it - as soon as Rubio rose to second place, Trump would cast doubt(VIDEO-AT-LINK)About a month ago, when Donald Trump was claiming that Ted Cruz probably was not eligible to be president, Trump was questioned by Jake Tapper about whether Marco Rubio was eligible. Trump exhibited some legal understanding of the issue, citing an op-ed written by Harvard Professor Laurence Tribe. Trump's conclusion was that he had no doubts Rubio was eligible: "It's a different [than Ted Cruz], very different thing because he was born here. He was born on the land."(VIDEO-AT-LINK)As the attacks on Cruz's eligibility rose...