SACRAMENTO  (AP) — Gov. Jerry Brown is sprinting into the final year of his third term as governor with a series of policy successes and powerful financial backers boosting his all-but-certain run for another term.

His voter-approved tax increases and relative restraint on state budgeting helped end years of deficits and have even led to projections of future surpluses.

He has given every indication that he will seek re-election and already has racked up more than $15 million in contributions for a potential campaign, far eclipsing the fundraising of any of his would-be Republican rivals.

“I’ve been down, and I’ve been up. And I’d much prefer to be up,” the 75-year-old Democrat said during a recent Atlantic magazine conference, referring to the approval of his job performance among registered voters (58 percent in one poll and 47 percent in another, both released in early December).

Yet he also faces a multitude of policy challenges that could potentially come to a head in 2014. They include his support for the $68 billion high-speed rail project, which is fast losing public favor and faces an uncertain future after a state judge ruled that current plans do not comply with the initiative approved by voters in 2008.

A $24 billion proposal to build two massive tunnels for shipping water from Northern California to Southern California has drawn opposition from the delta region and conservationists. And his landmark sentencing overhaul to address a federal court order on prison reduction is giving fodder to Republicans who raise the specter of a rising crime rate.

None of those concerns is likely to be enough to derail his path to re-election, though.

Brown has proven to be politically adept, persuading voters in 2012 to approve Proposition 30, which temporarily raises the state sales tax and income taxes on the wealthy. The infusion of an extra $6 billion a year helped the balance the state budget and allowed him to score points with the public by giving more money to schools.

He also had the good fortune to take office as the national economy was beginning to rebound and after voters approved an initiative allowing the state budget to pass with a majority vote in the Legislature rather than a two-thirds supermajority. With Brown’s fellow Democrats controlling the Legislature, the change ended the political gridlock faced by his predecessor, Gov. Arnold Schwarzenegger.

Having two-thirds majorities of Democrats in the Assembly and Senate at various points in the past year also has made governing easier.

“How much credit he can really take, I’m not so sure. I give him Prop. 30; I give him that hands-down,” said Larry Gerston, a political scientist at San Jose State University.

But he said California has benefited from the larger rebound in the nation’s economy.

“And so, when things are rolling, the governor takes a disproportionate credit for what’s happened. And when things are foundering, the governor gets disproportionate blame. He deserves neither the credit nor the blame,” Gerston said.

The governor’s rosy rhetoric about the state’s ascendency also might be out of step with the experience of many Californians. A survey by the Public Policy Institute of California released in December found that two-thirds of Californians believe the state remains in a recession and is divided between the haves and have-nots.

The state also continues to face a “wall of debt” that Brown has talked about, which includes at least $300 billion in unfunded pension liabilities and retiree health care, and about $10 billion the state owes the federal government for unemployment insurance claims.

Paying it down will be a challenge, however. With the nonpartisan Legislative Analyst’s Office predicting budget surpluses for the first time in years, Brown will face mounting pressure from Democratic constituencies to increase spending.

Those knocking on the governor’s door include groups seeking the return of money borrowed from special funds to help balance the budget, such as $1 billion in gas taxes intended for road repairs and $500 million in cap-and-trade funds intended for environmental protection.

Prominent environmental groups recently sent Brown a letter calling on him to commit the cap-and-trade money to environmental preservation or risk “losing credibility” on the issue. He also has been dogged by those critical of his decision to allow hydraulic fracturing, or fracking, of oil and natural gas in California.

Opponents hope to paint Brown next year as a product of the status quo who has failed to make necessary structural changes in state spending.

“He’s scratching the surface, checking a box and saying ‘Yep, I solved this problem, let’s move on to the next one,’” said Neel Kashkari, former U.S. Treasury official and potential GOP challenger to Brown. “But has he really addressed the unfunded pension liabilities? No. Has he really addressed education? No. Has he really addressed economic growth? No. But he can show a little bit of action on each of these, and then on to the next thing.”

A political spokesman for Brown, Dan Newman, called it “comical” that a candidate who helped lead the nation’s $700 billion bank bailout now is criticizing the governor who eliminated California’s massive deficit and put the state back on solid footing, “along with a litany of other accomplishments, which he seems to simultaneously acknowledge and dismiss.” The Troubled Asset Relief Program Kashkari helped lead eventually spent $422 billion.

In 2013, Brown signed legislation that raised the minimum wage for the first time in years, to $10 by 2016, and restructured the state’s school spending formula to direct more money to schools with the highest proportion of poor children and English-learners.

Brown has declined requests for an interview with The Associated Press.

In addition to Kashkari, two other Republicans are expected to challenge Brown: former Lt. Gov. Abel Maldonado of Santa Maria and Assemblyman Tim Donnelly, a tea party favorite from San Bernardino County.

The June primary is the first gubernatorial race under California’s top two primary system, in which the top two vote-getters advance to the November general election regardless of party, leaving the field wide open for the GOP contenders.

So far, polls have shown Brown’s three potential challengers have little name recognition and are not a serious threat if he chooses to run.

Those familiar with the governor know not to expect a formal announcement too far in advance of the March 7 deadline.

“I don’t jump into these things lightly, and that’s why I’ve not declared my intentions,” Brown told reporters at a Sacramento event in November, saying that he is concentrating on governing. “But at the same time, I am aware that in November of next year there will be an election, and I will make some decisions regarding that. I want to take the time that’s appropriate.”