While Romney and Cain are the current frontrunners, just a third say that their minds are made up, while two-thirds say they could change their mind. Cain has surged over the past three weeks, from just nine percent in late September, a net gain of 16 percent. That is roughly equal to Perry's fall; Perry led the field three weeks ago, with 30 percent of the vote. Romney, meanwhile, has gained a modest four points over that time -- well within the margin of error. The CNN/ORC International poll was conducted Oct. 14-16, surveying 416 registered Republican or Republican-leaning independent voters. The poll was released one day before CNN will air a Republican presidential debate from Las Vegas.