marco-rubio-mistress-president-pp On the heels of the New Hampshire primary, RadarOnline.com has tracked down the mystery woman who could bring down GOP Presidential hopeful Marco Rubio's entire campaign! Click through Radar's gallery to find out more about the woman at the center of a sleazy sex scandal.

marco-rubio-mistress-president-2 A new book revealed Marco — a married dad of four — once authorized a $40,000 probe into whether his rivals had dug up evidence he was hiding a "zipper problem!"

marco-rubio-mistress-president-4 The scandal focused on this woman, a shapely former GOP political operative who is younger than Rubio's wife, Jeanette.

marco-rubio-mistress-president-3 The woman's name first surfaced in records for a Republican Party American Express card that 44-year-old Rubio, who is also embroiled in a love child scandal, used when he was Speaker of the Florida House of Representatives. Those records showed he used the card to pay her expenses!

marco-rubio-mistress-president-1 A GOP insider told Radar evidence the pair might have been sexually involved came to light in 2009 when Marco faced then-Florida governor Charlie Crist in the U.S. Senate race.

marco-rubio-mistress-president-5 "A researcher briefed the [Crist] campaign on an email from [the woman] that said, 'I can't take this anymore. Why won't you return my phone calls?'" the spy said of newly nicknamed "Robot Rubio."

marco-rubio-mistress-president-6 "The email seemed an indication that he might have been having an affair with her, but the governor [Crist] didn't feel it was enough to substantiate it and go public," said the spy of Rubio, who has been married for 17 years.