SACRAMENTO -- Labor allies of Gov. Jerry Brown are actively considering backing moderate challengers in next year's Republican legislative primary campaigns with the aim of forcing GOP incumbents to think twice about opposing Brown's plan to push a tax extension measure on the ballot.
They are also considering ramping up direct mail efforts or door-to-door canvassing within the next several weeks in the districts of potentially vulnerable Republicans who continue to threaten to block a vote on Brown's tax plan.
The strategy hinges on two coming political changes that could rock California's political landscape: new district lines being drawn up this spring by an independent committee and top-two primaries, in which the top two finishers in primaries will move onto the general election, regardless of party, beginning in 2012.
"A number of groups are looking closely at this," said a Democrat close to the administration. "They'll all look for moderate Republicans in a top-two situation."
The powerful California Teachers Association, SEIU and California Labor Federation are all at various stages of thinking through the strategy, several sources said.
Republicans have so far rebuffed Brown's call for a special election in June, arguing that voters have consistently rejected taxes. They took withering shots from Brown during his State of the State speech Monday, in which the new governor called it "unconscionable" and "irresponsible" to prohibit voters from deciding how to handle the state's $25.4 billion deficit.
Brown must receive two-thirds majorities in both legislative chambers, and needs five Republican votes, to put his plan on the ballot. He is calling for a five-year extension of a 2009 tax increase for purchases, income and autos. He has also proposed $12.5 billion in program cuts, excluding K-12 education.
Democratic strategists are hoping that the mere possibility of a challenge from the center would convince a handful of Republicans that their job preservation lies in a vote for Brown's plan to put taxes on the ballot.
Republicans typically are wary of a backlash from the conservative wing of their party on tax votes.
"But Republicans understand the open primary is a different world," said Steve Smith, a spokesman for the California Labor Federation, which he said has yet to decide on its political strategy. "It opens the door to moderate Republicans in a way we haven't seen in the past."
Brown himself evoked the specter of political consequences after his State of the State address.
"I do think that thumbing your nose at voters of California is not an electoral path to success," Brown said.
He is calculating that there are enough Republicans who won't want to risk being attacked in a GOP primary for cuts that would devastate what he said are "core functions" of government: schools, universities and public safety.
Top-two primaries within district lines that produce more competitive races could result in moderate alternatives, analysts say. In a Republican district, Democrats and independents would have to combine with moderate Republicans to oust conservative incumbents, said Gale Kaufman, a Democratic political consultant who works closely with the California Teachers Association.
"Folks are looking at ways to elect more moderates," Kaufman said. "The open primary and redistricting allows you to have a conversation we've never had before."
Republican strategist Kevin Spillane said he doubts the strategy will work.
"I don't see anybody getting punished" by a vote against putting the tax issue on the ballot, he said. "You just don't see incumbents lose. The reality is voters have not been punishing incumbents for late budgets, unbalanced budgets or fiscal crises."
And while labor could inject resources that incumbent Republicans are unlikely to match, their presence alone could tilt an election to the conservative candidate, Spillane said.
"With Republicans, unions are particularly unpopular," Spillane said.
Republicans and their allies say that Democratic incumbents face the same conundrum: that a vote to put taxes on the ballot may incur the wrath of a more moderate electorate.
"It's a two-edged sword," said Jon Coupal, president of the Howard Jarvis Taxpayers Association. "There are going to be Democratic districts now dominated by union influence that Republicans will now have a shot at."
The redistricting commission is scheduled to produce new district lines in August, and lawmakers are closely monitoring the situation, said Allen Hoffenblum, a co-editor of the California Target Book.
Sen. Sam Blakeslee, R-San Luis Obispo, is one legislator who might have a particular interest in the newly drawn lines. His district is an example of gerrymandering excesses that led to voter approval of the new redistricting commission, snaking 230 miles up the coast from San Luis Obispo to the edges of San Jose.
Though he won a special election last summer over former legislator John Laird by attacking him as a liberal tax-and-spend Democrat, Blakeslee is one of only two Republicans to have not signed a pledge to vote against taxes.
And in what appears to be an effort to showcase moderate tendencies, Blakeslee formed a bipartisan select committee on tax reform.
But if he votes against putting Brown's tax plan on the ballot, labor sources indicated he would be a likely target in a GOP primary.
Blakeslee declined to comment.