On paper, Jerry Brown looks like he could give Hillary Rodham Clinton a scare. He's a governor with a compelling record of fixing California's budget and reviving the biggest state's economy. He's admired by liberals for his work to combat climate change and address immigration laws. And he caught the presidential bug long ago, running for the White House three times.

So why is Brown not stepping forward to challenge Clinton for the Democratic presidential nomination in 2016?

"Running against Hillary is like running against Jerry Brown in California," Brown, 76, said in an interview Friday at The Washington Post. "In the Democratic Party, it's not going to happen. You reach a certain point of party loyalty and it's very powerful."

In a wide-ranging interview with Post reporters, Brown said Clinton enjoys "the power of incumbency" as President Obama's former secretary of state and heir apparent. A primary challenge to her, he said, "doesn't look like a fruitful use of my time."

“I would say she’s extremely formidable and it doesn't appear that there’s anything that would block her path,” Brown added.

Brown disagreed with some leading Democrats who believe a strong primary challenge would actually benefit Clinton by helping her get into fighting strength before she faces the eventual Republican nominee in the general election.

"Primary oppositions are not helpful," Brown said, recalling his own 2010 race for governor when former eBay chief executive Meg Whitman was wounded after veering right in her rhetoric and positions to fend off a primary challenge from Steve Poizner.

"Some people think that strengthens the process or helps the candidate go through his or her paces," Brown said. But, he said, "the truth is it’s not helpful. The real competition has to start right away with a Republican-Democratic difference. There’s plenty there to create conflict and debate and do whatever you have to do to get ready for the November election. You can do that facing off against the Republican opponents, of which there’s so many, and there’s so many stupid things they’re saying. That’s a far better place than cutting nuanced differences with some Democratic insurgent."

That Brown is advocating an unobstructed glide path for Clinton to the Democratic nomination might come as a surprise given his own history. In 1992, Brown was Bill Clinton's most persistent and pesky Democratic primary opponent and for months refused to endorse him.

Asked in Friday's interview about the state of his relationship with the Clintons, Brown said very little. "It's all been written about," he said. An aide reminded Brown that he had met with Bill and Hillary several times over the past few years.

"We come from different parts of the country," Brown said. "I think I occupy a unique part of the party, and I don't find too many people in the same place....It’s a very small part of the party, unfortunately.”

Brown is in his second stint as California governor, after serving between 1975 and 1983, and has also been state attorney general and mayor of Oakland. He said he has more of a "western sensibility," especially on environmental issues.

When asked about the recent controversy over Hillary Clinton's use of a private e-mail account as secretary of state, Brown said he is not convinced the issue is a passing storm, as many other Democrats contend.

"I don’t know that," Brown said. “With these things, what makes a difference, you often don’t know until it unfolds because nothing is just what it is. It’s always in part of a larger context. Things unfold and things happen."