What to expect in 2012? Jon Coupal is preparing for "nuclear war."

As the president of the Howard Jarvis Taxpayers Association, Coupal will play a critical role in the effort to defeat any tax increases up for a vote next year.

He'll also be on the offensive. His group has proposed a spending limit and is backing another measure to curb unions' political influence by banning paycheck deductions to build campaign war chests.

Fighting revenue measures at the ballot box is not new turf for the 56-year-old leader of the group founded by Howard Jarvis, the driving force behind Proposition 13. Coupal has served at the helm for the last 10 years, scoring victories as voters rejected seven statewide tax increase proposals.

The nonprofit bills itself as a grassroots organization and raised $6.7 million in 2009, according to its tax filing.

But Coupal notes he's been outspent before, and has on his side a mailing list of 200,000 members – a third of whom he says are Democrats – and anti-tax credibility that comes with the Jarvis name.

He said he'll try to exploit a Legislature that lacks the confidence of Californians.

"The Legislature does these crazy things. It's a very easy sell to the voters to say, 'They want more money from you, while they're (giving staff raises), while they're doing high-speed rail, while they're doing, quite frankly, the Dream Act,' " he said, adding: "Every day that building gives us another nugget that we take to voters."

Coupal's clout doesn't stop at the campaign trail. His organization's stances have long guided GOP lawmakers' votes on tax legislation.

The passage of the majority-vote budget lessened the leverage of the GOP caucus, but Coupal's ongoing influence on issues that require GOP votes was apparent in the final hours of this year's session.

Gov. Jerry Brown, who once called Coupal one of the "four horsemen of the tax apocalypse," summoned him for a last-minute appeal on a proposed change to the corporate tax formula. But Coupal wouldn't take a stand without more time for analysis. It failed without the needed GOP votes in the state Senate.

Many GOP legislators say their ideology – and the political leanings of their constituents – create a natural alignment with HJTA.

"I can tell you that Jon Coupal, when he says things, or when the organization says things, I listen because I know they're in sync with my constituents," said Sen. Bob Huff, R-Diamond Bar, the likely Senate GOP leader next year.

The 2012 elections bring new political districts and a top-two primary system – factors that could dilute some of Coupal's anti-tax heft if GOP candidates move to the center to appeal to a greater swath of the electorate.

But Coupal sees an opportunity to make a mark in more legislative races, possibly by even endorsing moderate Democrats "who may not be perfect but certainly distinguishable from the hard-left candidates."

Endorsements from HJTA are considered the taxpayers' equivalent of the Good Housekeeping seal in many GOP-leaning districts.

"Sometimes you have to step on toes of people who have been your friends in the past," he said. "But I think what this organization has done is, we just call them as we see them."

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Call Torey Van Oot, Bee Capitol Bureau, (916) 326-5544.

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