The announcement, widely expected, was made in minimalist Brown style, with a post on Twitter.
There was none of the political fanfare that typically accompanies a campaign kickoff — no rallies, no placards, no reporters in tow — just the Democratic governor walking unannounced into the Alameda County elections office to file his paperwork.
The low-frills approach mirrors Brown's governing style and is indicative of his strong political position. He has large fundraising advantages over his opponents, and polls show him with wide leads over his declared Republican challengers.
"Jerry Brown has had very little interest in stagecraft or visuals or any other theatrics that have become associated with politicians," said Bill Whalen, a fellow at Stanford University's Hoover Institution who was a speechwriter for former Republican Gov. Pete Wilson. "It might be different if he felt there was any competition out there."
Brown had consistently deflected questions about whether he would run, even as he continued to raise millions in campaign contributions. On Thursday, with the June primary fewer than 10 weeks away and with Brown scheduled to make a speech to the state Democratic Party convention in Los Angeles early in March, the 75-year-old governor pulled the trigger.
A former seminary student whose father, Pat, served two terms as governor from 1959 to 1967, Brown sent a letter to supporters Thursday laying out priorities for the next four years. They include continued fiscal prudence, steps to shore up public employee pension funds and investment in water management, roads, public buildings and other infrastructure.
The governor also made references to his Jesuit training and his family's political history.
"By the grace of God and habits of perseverance instilled in me by my family, the Dominican nuns and the Jesuits, I am here and ready to go," he wrote.
Brown is already the oldest governor in the country and would be 80 at the end of a fourth term. But he said his decades of experience are an asset.
"At this stage of my life, I can say — without any hesitation — that I am prepared and excited to tackle these challenges and the many others that lay before us," he wrote. "In fact, there is nothing I would rather do."
Brown's challengers used his announcement to reiterate their views that he has failed to fix California's schools and economy and that many Californians are still struggling to get by.
"It's time for a new leader in Sacramento who will do the hard work of creating good jobs and giving every kid a quality education," Republican Neel Kashkari, a former U.S. Treasury official hoping to unseat Brown, said in a statement. "And that's the reason I'm running for governor."
Brown's announcement highlighted some of his achievements in the past three years, such as erasing a $27-billion deficit, giving school districts more control over education and rewriting custody laws to keep low-level felons in local jails rather than send them to state prisons.
Those public safety policies have been criticized by Republicans for overburdening already crowded jails and leading to the early release of dangerous criminals.
Another candidate for governor, Assemblyman
While Republicans sharpen their attacks, analysts say the road will be tough in this election.
"History is on Jerry Brown's side," Whalen said. "The political math is on his side and the money is on his side."