Whether this was their master plan all along or not, California Republicans could destroy crucial support for an extension of tax increases if Gov. Jerry Brown supports the legislators' series of reform proposals.

Most of the half a dozen or so reform ideas laid out Monday by five moderate Republican state senators would force Brown to confront major public employee unions such as the California Teachers Association and the California Correctional and Peace Officers Association.

These two groups, among others, helped bring Brown back to office by giving significant financial backing to his campaign.

The teachers union recently launched a campaign to lobby legislators to back the tax plan. Both would be expected to play major roles in corralling statewide support for a ballot measure extending the tax increases.

Brown and the Legislature can prolong a budget fight for about two more weeks, but any longer and the chances to hold an election before the tax increases expire on July 1 would be nil.

Brown's resistance to the proposals makes sense. If he adopted the proposals to get the support of at least four Republicans, he would get the tax issue on the ballot. As a consequence, he would likely significantly weaken the 53 percent support his tax plan currently enjoys. A climb up Mt. Whitney would suddenly seem more like an excursion to the top of Mt. Everest.

The Republicans made the budget talks even more complicated in their long list of reform demands, at least according to the handful of details they offered in an open letter to Brown. They want a hard spending cap for the state. Unlike other legislators, however, this group of five did not ask for the institution of a two-year budget cycle.

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Under a spending cap, surplus funds during years with revenues exceeding the cap would have to go paying off existing debt, infrastructure, building a reserve....and education. The teachers probably love that bone thrown at them, but other public employee unions would likely pick a bone with Brown. Prison guards, for instance, wouldn't mind seeing those rare surpluses go towards paying them or increasing their numbers.

The five Republicans also offer an education reform agenda. They fall short of calling for merit pay for teachers—which three in five Californians support. Instead, they call for “addressing teacher seniority and evaluation.” An April 2010 survey found Californians are split on whether seniority should be a factor in merit pay for teachers.

Their other concerns are “protecting parents' right to choose which school their children attend, providing more flexibility for school districts to fire bad teachers, extending school lay-off timelines.”

The Republicans also call for re-negotiating pension plans with state workers to make them more like 401(k) accounts. Those public employees would also be promoted, fired or see pay increases strictly based on merit.

The Republicans want more work to be open to bids from private contractors.

Among other desires are simplifying the state's tax code and regulatory measures. Those might involve laying off some state employees but are among the things Brown has said he's open too.

The Republicans summed up Brown's problem in their letter.

"We have therefore concluded that you are unable to compel other stakeholders to accept real reform," the GOP5 wrote.

To reach reporter Paresh Dave, click here.

Find him on Twitter: @peard33.