Antitrust laws are supposed to prevent this kind of market power. So why are giant health insurers like WellPoint exempt? Chalk it up to an anomaly that began seven decades ago in the quaint old world of regional, nonprofit Blues. They were created in part by hospitals to spread the costs of expensive new equipment and facilities over many policy holders. Collaboration was the point, not competition. The 1945 McCarran-Ferguson Act made it official, exempting insurers from antitrust scrutiny and giving states the power to regulate them, although not necessarily any power to regulate rates.

The system worked fairly well until about two decades ago when insurers began morphing into publicly held, for-profit cash machines. A new breed of medical entrepreneur saw opportunities to profit from a rapidly aging population eager to get every new drug and technology that might extend their lives, and a government committed to doling out hundreds of billions of dollars in Medicare and Medicaid.

With size has come not only market power but political clout. Big for-profit insurers deploy enough campaign money and lobbyists to get their way with state legislators and insurance commissioners. A proposal last year to allow California’s Department of Insurance to regulate rates, for example, died in committee. These companies have even been known to press states to limit how many other health insurers they license.

And when they can’t get their way, insurers go to court. In Maine  one state that aggressively regulates rates  WellPoint’s Anthem subsidiary has sued the insurance superintendent for reducing its requested rate increase.

Political clout can be especially advantageous at the federal level, as the big Wall Street banks have so brazenly demonstrated. Over the past two and a half years, WellPoint’s employees and associates have contributed more than $922,000 to federal political campaigns, and the company has spent $7.8 million lobbying Washington policymakers, according to the Center for Responsive Politics. It should not be surprising that WellPoint was one of the leading opponents of the public insurance option, which would have subjected it to competition even where it had sewn up the market.

Antitrust is no substitute for broader health care reform, but it’s an important prerequisite. If a handful of giant health insurers are allowed to dominate the industry, many of the other aspects of reform (establishing insurance exchanges, requiring people to have insurance, even allowing consumers to buy insurance across state lines) won’t bring down the price of insurance.

Regardless of what happens at the White House’s health care meeting on Thursday, we’ve got to make sure health insurers compete for every one of our dollars. First chance I get I’m going to find another health insurer here in California  unless Anthem has such a lock on the market I can’t find a better deal.