The three senators officially seeking the GOP nomination have been joined by two candidates with more experience in brain surgery and business than politics. "I'm willing to be part of the equation and therefore, I'm announcing my candidacy for president of the United States of America," retired neurosurgeon Ben Carson tells CBS 12. He's joined by former HP CEO Carly Fiorina, who confirms to George Stephanopoulos this morning that, yes, "I am running for president." The GOP field is filling up, notes the New York Times: Sens. Ted Cruz, Marco Rubio, and Rand Paul have already declared, and Mike Huckabee is expected to follow suit tomorrow. As for today's entrants, both Fiorina and Carson are emphasizing their status as political outsiders: