SACRAMENTO - John Burton is confronting one of the toughest tests of his career.

The 70-year-old colorful San Francisco liberal is leader of the state Senate and arguably the most powerful Democrat in the Capitol -- even, some say, more influential than the governor. There will be no state budget solution without his agreement.

Yet, the state faces a $30 billion shortfall, and Republicans are unwilling to yield on tax increases. So, with his Senate career due to end next year because of term limits, Burton is desperately searching for a way out of the crisis that will avoid undercutting programs for the poor and disadvantaged on which he has built his legacy.

"This is the worst (year). There's never been anything like it in the history of the state," Burton said Friday as he shuffled between meetings at the state Capitol. "I don't want them (the poor) to bear the biggest brunt of this thing. The more we keep focused on them, the less they get hurt."

A Democrat who followed in the footsteps of his older brother, the legendary Rep. Phillip Burton, the state senator has been a crusader for the underclass.

For those who know him well, the emphasis on social justice and protecting the disadvantaged is classic Burton. Many believe him when he says he came to Sacramento to fight for people who do not have lobbyists, political action committees or powerful advocates.

However, critics say Burton is also a consummate politician who serves the big-money interests of the Democratic Party and is pragmatic enough to know when and how to cut a deal.

Those two sometimes conflicting forces -- Burton's heart and his head -- have clashed, as he has agonized over what approach is best for the state's finances.

Burton's inner turmoil reflects the growing unrest among Senate Democrats. Since the magnitude of the state's record-high deficit became clear last December, they have pushed for higher taxes as part of the solution.

But now, with Republicans solidly sticking together in their opposition to tax increases and the state rapidly running out of borrowed cash, some Senate Democrats say it's time to abandon the call for new revenues. Sen. Tom Torlakson, D-Antioch, for one, has said he's willing to vote for a no-tax budget to safeguard the state from financial upheaval.

The GOP leader in the Legislature's upper house, Sen. Jim Brulte of Rancho Cucamonga, has watched Burton wrestle with the dilemma. "I think his caucus is divided ... and I think John is also conflicted," Brulte said.

Straight shooter

Burton grew up in San Francisco's Sunset District as the youngest of three boys. His father was a doctor who made it a point to treat minorities and the poor. At a time when fewer women worked, his mother was determined enough to get her own job so she could buy herself a car.

Burton credits his parents with instilling in him a work ethic and compassion for the downtrodden. As a young man, he loved playing basketball as much as watching the street characters that milled about the Tenderloin District, where he shined shoes.

It was there, he has said, Burton learned the value of being a straight shooter, a trait that has won him praise from Republicans and Democrats most of his adult life.

To wit, Brulte and Burton -- divergent in age, background and political philosophy -- share a rapport. Even in the midst of debating each other passionately on Tuesday, when the Senate voted down a GOP budget proposal, the two could be seen joking during intervals. Brulte describes the relationship as "professional, friendly, respectful."

Burton attended law school and then jumped into politics under the tutelage of his eldest brother, Phillip, winning a seat in the Assembly in 1964. He went on to Congress in 1974 and then became heavily involved in drugs and alcohol. In 1982, he quit to check himself into a rehabilitation center. He says he has stayed clean since.

At the request of then-Assembly Speaker Willie Brown, Burton returned to politics. He was elected to the Assembly in 1988 and then to the Senate in 1996. He outmaneuvered moderate Sen. Patrick Johnston, D-Stockton, much to the surprise of many in the Capitol, to succeed Bill Lockyer as leader of the upper house in 1998.

Under Burton's leadership, the traditionally buttoned-down and staid Senate has become increasingly powerful, benefiting in part from an Assembly weakened by term limits. It has also lost much of its patience, displayed a greater willingness to resort to political trickery and fostered poor relations with Gov. Gray Davis, said Bruce Cain, a UC Berkeley political scientist.

"Some of the Senate's behavior is John's personal style," Cain said. "It will be interesting to see if the Senate gets a different style with the next leader, and whether it is less impatient both with the governor and the other house."

Streetwise smarts

To the uninitiated, Burton's style is both crude and endearing. He is famous for his temper and profanity-laced tirades. But Burton's eruptions pass quickly, and those around him say it shows his uncommon commitment and passion.

Burton is also known to turn on the charm or break into song and dance at a moment's notice. He disarms people with a mixture of honesty, quick humor and plain, streetwise smarts.

To Cain, Burton is more political animal than compassionate liberal. Indeed, some say Burton uses his emotions, outbursts and quests for social justice as tools to get what he wants, which often has more to do with the Machiavellian world of controlling political power and padding campaign funds.

Burton has cleverly focused on the impacts of budget cuts to the poor, Cain said, when in reality he is equally interested in protecting the Democratic Party's big contributors, from teachers to the prison guard union.

"Moreover, Burton is not about to eliminate the social programs he believes in but is smart enough to keep them alive, even with less funding," Cain said. "I don't think this is a guy who is going home right now and losing sleep at night."

Christine Minnehan, a lobbyist for the Western Center on Law and Poverty, said Burton is a shrewd, skillful negotiator who has taught her how to temper her idealism with political pragmatism. Burton is a "greedy realist" who knows when to take the best offer, she said.

"I think he is enraged and sickened about the choices he has to make on the budget," Minnehan said. "He also realizes that if he does not maintain a grip on his fury, he won't be able to get the sharpest deal that preserves the maximum amount he can get."

But, still, there's only so much Burton can do.

"It's up to the economy," Burton said. "The federal government's now got one of the largest deficits in history thanks to the war and tax cuts. It's not limited to us; it's all over the country."

As for how to bridge the state's deficit in a way that will win the blessing of the Legislature without slashing programs for the poor, Burton said he didn't have the magic answer. "I will not know 'til we do it. (I) just hope to get out alive."