(CNN) — A prominent surrogate for John McCain on Thursday raised Barack Obama's admitted cocaine use as a teenager and said the Illinois senator should speak candidly about it to the American people. Speaking to Dennis Miller, a comedian and conservative radio talk show host, former Oklahoma Gov. Frank Keating said Obama should be more forthright about his background and what he called his "very extreme" record. "He ought to admit, ‘You know, I've got to be honest with you. I was a guy of the street. I was way to the left. I used cocaine. I voted liberally, but...