If it's possible to encapsulate the volatility and uncertainty of the 2012 Republican presidential race in a single chart, the one below might fit the bill.
It tracks the results of the 13 national CNN/ORC polls this year measuring the preferences of Republican primary voters. It also separates the results into three categories: the overall leader, the leader among the roughly half of the party that identifies with the tea party, and the leader among the roughly other half that does not.
The chart points to several large conclusions. First is how fluid and unsettled the race has been. Five different candidates (including three that did not run, Mike Huckabee, Rudolph Giuliani, and Donald Trump) have held the overall lead in the survey; not since 1964 have so many different candidates led in a GOP presidential race in the year before the voting.
Within the two evenly balanced wings of the party, there's even more fluctuation. In the 13 polls, six different candidates have led among tea party supporters: Huckabee, Giuliani, Mitt Romney, Rick Perry, Herman Cain and most recently Newt Gingrich. Among those who don't identify with the tea party, a similar group of six candidates have held the top spot: Sarah Palin, Gingrich, Trump, Romney, Giuliani, and Perry.