Romney raised $56 million during 2011, more than double the amount raised by any of his Republican opponents, and refrained from spending his own money on the campaign. He initially pursued a low-key, low-profile strategy. Michele Bachmann staged a brief surge in polls, which preceded a poll surge in September 2011 by Rick Perry who had entered the race the month before. Perry and Romney exchanged sharp criticisms of each other during a series of debates among the Republican candidates. The October 2011 decisions of Chris Christie and Sarah Palin not to run effectively settled the field of candidates. Perry faded after poor performances in those debates, while Herman Cain's 'long-shot' bid gained popularity until allegations of sexual misconduct derailed it.