The CBO examined the effect of ending the anti-trust exemption and found:

Based on information from the Justice Department, the Federal Trade Commission, the National Association of Insurance Commissioners, consumer groups, and private attorneys, CBO estimates that both of those effects would be very small, and thus that enacting the legislation would have no significant effect on the premiums that private insurers would charge for health insurance. Changes in those premiums can affect federal revenues because of the favorable tax treatment that is accorded to employment-based coverage under current law, but any such effects of the legislation would be negligible in CBO’s estimation.

Senate Majority Leader Harry Reid along with other Democrats made a big show about pushing to eliminate the antitrust exemption for insurance companies. While it maybe decent policy it should have very little effect on the health insurance market. The CBO echos the find of some analysts who have also concluded that the change would be a very minimal. If the move is meant to punish the health insurance companies it is at best a light slap on the wrist. If Democrats want to show that they are being tough on the health insurance companies, then we need some real fire, not so much smoke and mirrors.