Sept. 10, a little less than five months ago, 22 of the 24 Democrats in the California Senate voted for a healthcare reform plan that was based on financial assumptions modeled by MIT healthcare economist Jonathon Gruber.

Its intent was to extend healthcare coverage to millions of uninsured Californians, and the chief mechanism for doing that was to create a statewide purchasing pool that would buy policies for uninsured workers. It would have been funded by fees from employers who chose not to directly provide health benefits to workers.

The senators cast their votes for AB8 knowing that Gov. Arnold Schwarzenegger would likely veto it, but presumably they were confident that the bill was financially sound.

Monday, five of those same Democratic senators voted in committee to kill a comprehensive healthcare reform plan that was also based on financial assumptions modeled by Gruber. It also included the purchasing pool and the employer fees. This one would have been signed by Schwarzenegger had the Senate sent it to him.

Their chief rationale for voting it down was that the financial assumptions were flawed.

What changed between then and now?

The short answer is that they got cold feet.

The longer answer is more complex and includes such factors as bruised senatorial egos, mounting pressure from an energetic special-interest group and a deteriorating economy.

To be sure, there were some notable differences between AB8 and the compromise bill. Chief among them was the inclusion of an individual mandate, a requirement that was softened by a higher level of subsidies than the earlier bill.

But it wasn't the individual mandate the new foes chiefly cited; rather, it was a born-again concern about financial risks.

Providing cover for this concern was a report that had been issued a week earlier by the nonpartisan legislative analyst, which said the plan would be in financial jeopardy if the costs of premiums turned out to be higher than anticipated. The analyst also noted that any plan that attempted to tackle the complex issue of healthcare reform would involve long-term risks.

The naysayers also professed concern about creating a new program during an economic downturn. But the program on which they were voting wouldn't have begun offering health insurance until July 2010.

In all likelihood, by then the economic cycle will have run its course. Asked to make a decision about a long-range investment in the health of Californians, they got spooked by the circumstances of the moment.

The senators were clearly put off by the political situation of having only the options of embracing or rejecting the plan. The timing was such that they couldn't tinker with it, a reality that collided with their senatorial sense of self-importance.

As for what created that situation, there is ample blame. Had Schwarzenegger not put off engaging in detailed negotiations until late last year, perhaps the deadline to meet a 2008 ballot deadline would not have come into play. And had even a handful of Republican lawmakers chosen to negotiate in good faith with a governor of their own party, going to the ballot would not have been a necessity.

The monthlong delay between the Assembly's approval and Monday's Senate committee vote also proved a Sacramento truism: Give special interests time and they can kill anything. The California Nurses Association, a liberal interest group that can make life miserable for any Democrat, used the time to its advantage.

There was one opponent who cannot be accused of backing down from previous support for private insurance-based reform. Committee Chairwoman Sheila Kuehl was the only Democrat who voted against AB8 last fall.

Kuehl insists that cost-effective, truly universal healthcare can be realized only through a single-payer system that creates a government-run insurance system. One might call Kuehl stubborn — or, perhaps, visionary — but she can't be faulted for flip-flopping or wilting under pressure.

That can't be said for the other Democratic senators who killed the plan: Elaine Alquist of San Jose, Gil Cedillo of Los Angeles, Gloria Negrete-McLeod of San Bernardino, Darrell Steinberg of Sacramento and Leland Yee of San Francisco.

Following Monday's vote, Anthony Wright, executive director of the advocacy group Health Access, said lawmakers had squandered an opportunity for reform that comes along perhaps only once a decade.

A Public Policy Institute of California survey this month showed 60 percent public support for the reform plan.

"We had an electorate poised to support meaningful healthcare reform," Wright said. "Now they won't get the chance."

— Timm Herdt is chief of The Star's state bureau. Read his political blog "95 percent accurate*" at http://www.VenturaCountyStar.com/herdt.