State Insurance Commissioner and mild-mannered former optometrist Mike Kreidler has never had the high-profile of his headline-grabbing predecessor, Deborah Senn, who led a crusade against health insurers that charged too much and gave too little. Kreidler, working behind the scenes on the dry minutiae of rates and practices, made the job seem boring again.

But he has a backbone that can surprise you, and it’s currently in full evidence. Kreidler has called for a ban on insurance companies’ use of credit information to set their rates. He labels the long-controversial practice “discriminatory and blatantly unfair.”

The problem with so-called “credit scoring,” according to Kreidler, is that it uses arbitrary and sometimes downright bizarre criteria. Someone could be penalized for buying a couch at Macy’s and taking advantage of an option to pay six months later with no interest. Cancelling or consolidating credit cards can also result in a lower score, according to his office.

“What do any of these practices have to do with how these people drive their cars or how they treat their homes?” he asks.

A lot, insists the insurance industry. “What’s important to remember is that consistently, across the board, people with lower credit ratings tend to file more claims,” says Darrin Sanger, a spokesperson for the Northwest Insurance Council, a Seattle-based trade group. The industry argues that if it can’t use that information to predict its losses, rates will go up for the vast majority of people.

Such threats scared Oregon voters from passing a credit-scoring ban in a 2006 ballot measure, and prompted this state’s legislature to say no to a ban when Kreidler first raised the issue shortly after taking office in 2002. (That same year, Maryland passed a ban in regard to homeowners’ insurance, and the industry claims rates have consequently gone up.)

Kreidler is pointing to the economy as a reason to re-open the issue, saying more people now have lower credit scores and are consequently being hurt by this practice. Recession politics might make legislators more receptive to his call.

But his spokesperson, Sandi Peck, concedes the insurance industry will likely fight this tooth and nail. A four-hour hearing on the measure last week was packed with industry lobbyists and consumer advocates. Looks like Kreidler has a good old populist battle on his hands.