Candidate Gavin Newsom promised the people of California that he would get them universal health care. Gov. Gavin Newsom is not going to fulfill that promise. And that’s fine. He won’t be the first politician to make a commitment on the campaign trail that didn’t happen once he took office. He certainly won’t be the last

During his campaign, Newsom’s most ambitious commitment was to provide health care to all Californians through a government-run, single-payer system. This declaration allowed him to separate himself from the other Democrats in the race, making him not just the early front-runner, but also the preferred candidate for the party’s energized progressive base. His most prominent opponent, former Los Angeles Mayor Antonio Villaraigosa, dismissed Newsom’s goal as “snake oil,” but it’s entirely possible that Newsom would not have been elected without making such a pledge.

Newsom talked stirringly about “bolder colors and bigger ideas.” But for those who listened closely, Newsom’s language became more measured as his lead in the polls grew. Words like “inevitably” and “ultimately” began to creep into his conversation. He told The Chronicle last spring that single-payer “is not an act that would occur by the signature of the next governor,” at least theoretically extending the timeline beyond the end of his second term in 2027. “There’s a lot of mythology about that,” he added.

Words like “mythology” rarely make it onto campaign bumper stickers, and so it appears that Newsom is subtly trying to prepare his supporters that while universal health care may be a worthwhile objective, it is not going to become a reality in California in the foreseeable future. It may be wise to mark the arrival for Newsom’s single-payer health care plan on the calendar for the same week as completion of Jerry Brown’s high-speed rail, Donald Trump’s border wall, and Colin Kaepernick’s induction into the Pro Football Hall of Fame.

The obstacles that will prevent Newsom from keeping his word are far beyond his control. The federal government would need to go along with such a plan, and neither the Trump administration nor a Republican-led Senate is likely to sign off. (Even a Democratic-controlled House would be a challenge: There are a lot of members elected in swing state districts that Trump carried in 2016 who may not want to defend a vote like this one.)

The other large-scale problem for a single-payer system is the sheer financial cost. Last year’s legislation that would have implemented such a plan carried a price of roughly $400 billion. The most optimistic projections predict that half of that money would come from existing federal, state and local government programs. But this would still require tax increases on a scale never before seen in California — or anywhere else. Newsom has now begun to refer to himself as “the adult in the room,” which suggests that he is not interested in budget-busting on such a grand scale.

Through no fault of his own, Newsom will never achieve his audacious goal. But he still intends to spend tremendous amounts of government money on a more generous health care system for Californians. Even in the face of a likely economic downturn, he will move forward with expansive and expensive programs to extend coverage to more state residents.

But that won’t be enough for many of his supporters. Voters tend to hear what they want to hear, and his most progressive backers will not back down simply because their candidate has. The California Nurses Association has been an aggressive and savvy advocate for a single-payer system for years, and it intends to apply maximum pressure on Newsom to fulfill his commitment — right now.

The question then becomes what his allies will accept as a reasonable compromise. There are already heightened expectations that Newsom will expand Medi-Cal services for undocumented immigrants, and take steps to shore up the state’s health exchanges and subsidize prescription drug costs. These would represent much larger expenditures than Brown was ever willing to make, but it’s still a long way from universal coverage. They will almost certainly want much more from the new governor in exchange for their continued support.

Newsom ran on a slogan of “Courage for a Change,” so the new governor may want to consider a display of bravery in which he levels with the Californians who actually believed his campaign promise.

Dan Schnur teaches at the University of Southern California’s Annenberg School of Communications and UC Berkeley’s Institute of Governmental Studies.