In case you're wondering, that is known as a euphemism. One duty assigned to a euphemism is softening or obscuring meanings about someone who cannot be relied upon to say what s/he really believes. We already had a perfectly good euphemism in this case, the "credibiility gap." That one was invented 46 years ago to describe Lyndon Baines Johnson's public statements regarding what he was doing in Vietnam. Sen. William J. Fulbright, who became an outspoken critic of the escalating war in Southeast Asia, can be credited for making "credibility gap" go viral.
What are we really talking about here? These guys lie through their teeth. Do that often enough, get caught at it enough times, and at least some people on your side of the political spectrum will begin to doubt the truth of anything that comes out of your mouth. It's called trust. And nearly half the people expected to vote for the two candidates most likely to win the Republican presidential nomination don't trust them.
More respondents in the poll, two-thirds, give a higher mark to a candidate who doesn't have a chance of getting the nomination: Ron Paul. He, they say, can be relied on to say what he means. Saying what you mean clearly and consistently can, of course, get you into trouble at the ballot box. For Romney and Gingrich and way too many other politicians, risking a credibility or authenticity gap appears safer than telling the truth. Such is the state of the nation.