Speculation continues to grow that Gov. Chris Christie will be asked to be Mitt Romney's keynote speaker in the upcoming Republican National Convention or even his choice for running mate.

All the talk of Christie on the national stage has sparked a debate among his supporters and critics about his role as a campaigner.

Romney is expected to make a decision on his running mate as early as this weekend. Other names in the mix besides Christie include Rep. Paul Ryan, former Minnesota Gov. Tim Pawlenty, and Sens. Marco Rubio and Rob Portman.