U.S. commentators were split on Friday as who emerged as a winner of Thursday's vice president debate, and instant polls conducted after the debate also showed markedly different reaction from voters.

A CNN/ORC International nationwide poll found the two participants in the debate, Vice President Joe Biden and Republican vice presidential nominee Paul Ryan, in a dead heat. Forty-four percent of the 381 voters who watched the debate, said Biden was victorious, while 48 percent thought Ryan did better. However, the debate audience was more Republican than the country as a whole, and the four-point difference is within the survey's sampling error.

A CBS News survey, however, found 50 percent of the 431 debate watchers believe Biden won, while 31 percent felt Ryan won. Another 19 percent said they felt it was a tie. The poll was conducted among uncommitted voters immediately following the debate.

Commentators were also divided, with Republicans believing Ryan won while Democrats saying Biden prevailed.

Republican strategist Karl Rove told Fox News that "Ryan's pitch was to independent voters. It was: We've got a plan. We understand the big problems. We've got a plan to deal with them... Joe Biden did do some good for the Democrat ticket by basically making up for some of the absence of energy and focus and aggressiveness."

Democrats, however, believed Biden commanded the stage, but were worried his aggressiveness and constant smirks could undo his efforts. A New York Times analysis said the party's combative liberal base felt Biden's aggressiveness is both "appropriate and overdue," while others could view his performance as condescending or over the top and unworthy of his office.

No matter how the debate was interpreted, both campaigns are seeking to capitalize on it. Ryan will be holding a rally in Lancaster, Ohio in the afternoon, joined by Republican presidential nominee Mitt Romney. Biden will go into Ryan's home turf, and deliver remarks in La Crosse, Wisconsin earlier in the afternoon.