The San Francisco Chronicle assembled the four Democratic candidates for governor Tuesday to talk about the “state’s big issues” and whether they “have the ideas and resolve to meet them.”

After 75 minutes of back and forth, moderated by Chronicle editorial page editor John Diaz, it was clear that the four mostly believe that dealing with the “big issues” will require spending a lot more money.

Spending more was mentioned repeatedly in responses about K-12 education, colleges, homelessness, the state’s housing shortage and, most expensively, universal health care.

And how will those additional billions of dollars be raised, especially since the four generally agreed that the state’s current tax system is out of whack, with the state budget already too dependent on volatile taxes from a relative handful of high-income Californians?

The responses became pretty murky on that point, paying lip service to tax reform without specifics. “We know what needs to be done,” Lt. Gov. Gavin Newsom offered, without saying what that may be.

Treasurer John Chiang was equally obtuse, calling for a “better balance among the three major streams (of taxes).” Likewise Antonio Villaraigosa, the former mayor of Los Angeles, who said he would “approach it (tax reform) comprehensively…”

The most forthright of the four on the tax issue was the one running the lowest in the polls and having nothing to lose, former state schools Supt. Delaine Eastin, who declared flatly, “It’s time to revise Proposition 13.”

She wants what unions and other liberal groups have been seeking ever since Proposition 13 was passed nearly 40 years ago—a “split roll” that would, in theory, maintain the measure’s benefits for residential property but allow property taxes on commercial property to rise unfettered.

It would take a ballot measure to change Proposition 13, which is lodged in the state constitution. But were a split roll to be approved, it would generate billions of dollars more in revenue for local governments and schools and relieve pressure on the state budget, which provides most of the education financing now.

However, a split property tax system would not come close to providing the tens of billions of dollars, or even hundreds of billions of dollars, that would be required to finance the candidates’ to-do lists. And Californians’ tax burden is already one of the nation’s highest, as a percentage of personal income.

That was especially evident when it came to universal health care, which is the most burning Democratic Party issue these days, thanks to pressure from the party’s resurgent left wing.

All are in favor of it, conceptually, with Newsom, who leads in the polls, and Eastin most vociferous. Villaraigosa and Chiang are somewhat less effusive, citing the high cost of expanding health care coverage to as many as 3 million Californians who lack it.

“We can’t cover everything,” Chiang offered. “You can’t sign something like that without a plan,” Villaraigosa said.

One of the four will almost certainly be the next governor, and the Chronicle’s effort to have them respond to major issues—even though water and poverty were not on the list—was a worthy one.

However, if they are serious about doing all the wonderful things they say they want to do, they should also have the guts to say who will be coughing up the many billions in taxes to pay for the goodies.