Nate Silver notes the stunning unpopularity of the current GOP field:
In the previous five competitive primaries — excluding 2004 for the Republicans, when Mr. Bush won re-nomination uncontested — each party had at least two candidates whose net favorability ratings were in the positive double digits, meaning that their favorables bettered their unfavorables by at least 10 points. All five times, also, the nominee came from among one of the candidates in this group. Republicans have no such candidates at this point in time.
This doesn't strike me as something Republicans should worry about. As Brendan Nyhan points out, presidential contenders are rarely popular at this stage of the game. Indeed, Nyhan digs up polling numbers to demonstrate the low significance of early polling. In January 1979, Ronald Reagan was at 38 percent favorability and 39 percent unfavorability. Likewise, Bill Clinton began 1991 with favorability numbers in the low teens (15 percent/12 percent). In the last two decades, the only presidential candidates with high favorability have been ones with pre-existing public profiles. Bob Dole, for instance, began 1995 with his favorability in the 70s.
At this stage of the presidential contest, "favorability" reflects public familiarity with the candidates. As the presidential race heats up, and candidates enter the public eye, partisan affiliations will kick in, and Republican-leaning voters will contribute to higher favorability ratings for the GOP slate. By the time the nominee is chosen, partisan rallying will ensure that the candidate has high favorability ratings, even if they began as a virtual unknown. At best, current polling for GOP candidates makes for interesting trivia, and Republicans should ignore it.