Back in June, more than 60% of Californians supported it.
But on Tuesday night, more than 60% of Californians voted against it.
What went wrong with Proposition 45, the once popular rate-review ballot initiative?
Here's a list of potential factors — and it's hard to pick just one.
It was outgunned
Prop. 45 had several high-profile champions. The measure was introduced by Consumer Watchdog and backed by insurance commissioner Dave Jones (D). The commissioner's support was unsurprising, given that Prop. 45 was intended to give Jones the power to veto excessive rate hikes by health insurers. (Currently, the Department of Insurance can review proposed rates but cannot deny them.)
And the initiative was overwhelmingly popular, at least to start. More than 70% of respondents to a Field Poll conducted between June and July signaled that they planned to support it.
(See this September "Road to Reform" column for more context on why Prop. 45 was so popular.)
But backers of the measure were quickly crowded out, as health insurers poured millions of dollars into the debate.
Supporters of Prop. 45 raised less than $3 million.
That disparity led to blanket ads that helped sway the electorate, with many commercials hammering away on a critical message: That "one politician in Sacramento" shouldn't have the power to steer health insurance rates for the state.
By early October, it was clear that support for Prop. 45 had eroded; a second Field Poll found that just 41% of likely voters backed the measure.
A Public Policy Institute of California survey demonstrated how the negative campaign was having a tangible effect: Between September and October, opposition to Prop. 45 grew by eight percentage points among Democrats and 14 percentage points among Republicans.
It was too adversarial
Prop. 45 may have been doomed once several traditional supporters of liberal causes, including the Service Employees International Union, elected to oppose it, too.
"When people get conflicting accounts from different parties with intuitive positions, they tend to discount them both," the Bay Area Council's Micah Weinberg pointed out to California Healthline.
"But when progressive Democrats agree with the conservative business community on something it gets people's attention. [And] here they both agreed Prop. 45 was problematic."
It was weakened by Proposition 46
A different ballot measure — Prop. 46 — was also championed by Consumer Watchdog, and was intended as a patient safety reform.
The initiative was essentially three separate proposals: To lift the cap on malpractice awards; to require mandatory drug testing for doctors; and to require doctors to check the prescription-drug database.
But for Consumer Watchdog, devoting resources to champion Prop 46 meant there were fewer resources to devote to defending Prop. 45, too.
And both ballot measures drew heavy resistance from the health care industry.
Nearly $60 million was spent to defeat Prop. 46 — essentially, seven times what was spent to support it.
"Medical malpractice insurers wanted to make sure this one went down," April Dembosky wrote for KQED's "State of Health" blog.
It was unnecessary
Democrats visibly split on Prop. 45, with Covered California leaders initially disagreeing with Jones about whether the measure was even necessary before electing to remain neutral in the debate.
Some Democrats had no restraints, however. House Minority Leader Nancy Pelosi (D-Calif.) even called Prop. 45 the way to "kill the Affordable Care Act."
Many observers said they were confused by the motive behind the measure.
A number of editorials wondered if Prop. 45 was even needed, given insurers' low rates for year 2 of the ACA insurance exchange.
"The dust has settled over the rollout of the Affordable Care Act, aka Obamacare," read a Bakersfield Californian editorial last month. "The Covered California health insurance exchange seems to be working; and insurance companies seem to be holding off on rate increases."
"Proposition 45 appears to be a fix for a problem that doesn't exist."
It was bound to fail
When it comes to California's ballot initiatives, there's a "dirty little secret," according to University of Southern California's Dan Schnur.
"They hardly ever pass."
That's not quite true; several ballot measures passed on Tuesday night, including Proposition 47, changing how some crimes are punished. But that measure had broader support and faced less active resistance than Prop 45.
"It's a very, very rare initiative that grabs enough public attention to overcome significant spending against it," Schnur told the Los Angeles Times.
"With the exception of a relatively small number of people, there's no one who feels very passionate about which government entity oversees healthcare premiums."
Around the nation
Here's a look at what else is making news on the road to reform.
What does a Republican Senate mean for Obamacare? Expect a politically symbolic repeal vote, followed by more targeted attacks, National Journal's Sam Baker reports.
Insurance exchanges still have 'back-end' issues. For the second straight year, the marketplaces will be plagued by data collection and transfer problems — even if those issues aren't visible to consumers, Robert Calandra writes for the Philadelphia Inquirer/Kaiser Health News.
Medicaid expansion faces new hurdles in old states: Republicans won control of the governorship in several states that had already decided to expand Medicaid expansion. In some cases, those governors-elect are hinting at making changes to the expansion, Virgil Dickson reports for Modern Healthcare.