Ever since state voters approved two tax measures on the November ballot and elected a Democratic supermajority to the state Legislature, we've heard rumblings about Proposition 13 -- whether it's time to change the landmark tax-slashing initiative passed in 1978, and if so how it should be changed.

Thirty-fours years after Prop. 13's passage, perhaps the time indeed has come to start a discussion about our state's tax structure. That doesn't mean an outright rollback of Prop. 13 but rather a debate about how to best retool our system of taxation in order to fortify vital support services at both the local and state levels to the degree the public demands.

So far, no one has mentioned rolling back the hallmark cap on residential property tax increases. While this provision has created just as much trouble as any other in Prop. 13, polls show consistent public support for it, so it seems wise not to mess with it. But other areas are ripe for reform.

Assemblyman Tom Ammiano, D-San Francisco, has proposed changing the method of taxing commercial property, imposing a so-called "split roll" that would tax commercial property at market value. Since commercial property changes hands much less often than homes, it is reassessed less often and therefore enjoys far more benefits from Prop. 13 than residential properties.

Though Ammiano's colleagues have given it a lukewarm response, and it terrifies the business community, it could significantly impact tax revenue. Take Kern County, for example, with its vast tracts of land owned by energy companies, mainly oil and gas but increasingly wind companies, too. The current combined value of that land exceeds $35 billion. Significant new revenue would result if those properties were reassessed more often and taxes paid on property values that were closer to the actual market value.

Other proposals -- and the ones getting the most traction -- target Proposition 13's requirement mandating a two-thirds majority vote for local governments wishing to raise special taxes. These lesser-known and less understood restrictions created by Prop. 13 are what have largely contributed to the centralization of control in Sacramento over local services. In short, these rules have hamstrung local governments' ability to fund local services that local voters want and need.

Sen. Mark Leno, D-San Francisco, has proposed that parcel taxes to fund school operations be allowed to pass with 55 percent of the vote. He argues that the change would give local voters the flexibility to raise taxes to fund libraries and music programs or improve teaching. Assemblyman Bob Blumenfield, D-Woodland Hills, has been advocating to lower the vote for all local infrastructure bonds to 55 percent.

It's completely reasonable to question the need for a two-third majority of the vote to raise special taxes locally, as these two proposals do. What justification is there to require such an overwhelming percentage of the vote?

Remember Measure I, Kern County's attempt to raise the sales tax a half-cent to help fund local roads and make the county eligible for more federal money? It garnered roughly 56 percent of the vote in 2006 but failed to meet the two-thirds requirement. In tax-averse Kern County, 56 percent is a major victory on a tax increase. More recently, Los Angeles County voters in November overwhelmingly supported a measure to increase sales tax to pay for transit. But a mere 66 percent of the vote wasn't sufficient: It fell a half-percentage point short of the two-thirds threshold.

It's too soon to endorse any one proposal at this point. And we'd prefer to see more comprehensive reform than bills here and there that target certain aspects of Proposition 13. But the debate on how to restore more local control -- yes, in the form of greater flexibility to raise taxes -- is long overdue.

A call for debate on this topic is not to be confused with a call for more taxes. But there's no denying the tax system that supports California today is broken. And it's long past time to explore ways to fix it.