Barry Pump rebuts McCarty, Poole, Romer, and Rosenthal’s argument:
bq. McCarty, Poole, Romer and Rosenthal argue that by withholding his vote, Feingold made Scott Brown the pivotal 60th senator, instead of either Susan Collins or Olympia Snowe…As a result, Brown was able to extract a compromise from Senate-House leadership during conference that ended a surcharge on large banks…so the final outcome was more conservative than if Feingold had allowed Collins or Snowe to play the pivotal role. MPRR assume, though, that Collins or Snowe would have supported the conference committee compromise on the surcharge and voted for the bill if they had been in the pivotal 60th vote position instead of Scott Brown.
bq. Is there any evidence of this? Actually, no.
He goes on to note that Susan Collins opposed the surchage as well. There is more in his post.