I am in favor of eliminating the McCarran-Ferguson Act's antitrust exemption of the insurance industry. In theory, there is no real reason to have it anymore. Bob Klein and I wrote a paper last year for the Searle Center on Law, Regulation, and Growth that essentially made that argument. We also said that due to interpretations of the exemption over the last fifty-years, there really is nothing the insurance industry does in a collaborative way that wouldn't pass muster (e.g. data sharing) under a rule of reason analysis.
So what's the big deal? Why the push to eliminate the exemption? I think people think that there is so much corruption in insurance that we need to punish them and removing the antitrust exemption is the first step. Or perhaps, somebody believes there may be "go-away" money in putative Sherman Act suits against the industry. I know that this is what the opponents of MFA repeal are thinking. While they believe that they would prevail under a rule of reason analysis, the costs of successfully litigating their polices is high.