POWER RANKINGS: It's Cruz's turn in the spotlight

Lindsey Graham’s withdrawal won’t prove terribly significant, but it may mark the beginning of the thinning of the GOP herd. With less than six weeks until Iowa, only a handful of candidates are polling above the level of statistical noise. If they start dropping out, it could allow voter — come the New Year — to focus on the real contenders.

Currently, Ted Cruz is the center of the race. He trails Donald Trump in national polls, but is leading big in Iowa. In the most recent debate, the Rubio-vs.-Cruz scuffles were the most interesting, and perhaps the most consequential.