The health insurance industry in California has been quick to voice its qualified support for a proposal announced last week by Gov. Arnold Schwarzenegger that would require all state residents to obtain health insurance.

Their reaction suggests how much the political momentum behind health care reform efforts has intensified and how health insurers plan to cope, or even benefit. The new proposal could expand the industry's market by four million to five million currently uninsured Californians something health plans have been unable to do despite heavily marketing new products to some segments.

However, health insurers have raised concerns about some parts of the proposal, such as a provision that would require insurers to spend 85 cents of every dollar in premiums on health care and a provision that would require insurers to sell policies to all California residents, regardless of whether they have medical conditions.