If Jerry Brown were ten years younger, would he be Hillary's main challenger?

[Fuzzy Bear]

I gave a kind of half-hearted "yes".  The Jerry Brown of 1976 was, in the end, Carter's main challenger, because he came from California, the largest state, and because he filled a neo-liberal niche that seemed trendy, but attractive to moderate and cross-over voters.  California is now solidly Democratic at all levels, and if Brown were 10 years younger, he wouldn't be a two-separate-administrations Governor of California; he was pretty young the first time out.

Still Jerry Brown WAS the main challenger to Jimmy Carter in 1976 (when it all shook out) and he was the main challenger to Bill Clinton in 1992 (outlasting Paul Tsongas).  He wouldn't be viewed as Hillary's main competition, but if he ran, he'd end up that way. 

[Fuzzy Bear]

What makes Jerry Brown (at any age) less of a factor in Presidential politics is the diminishment in the importance of California in Presidential Politics, along with New York and Texas. 

I cannot remember the title of the book I read, but it was a book that predicted the 1972 election.  The predictions turned out to be way off, but they may not have been if a more centrist Democrat other than McGovern had been nominated and if that nominee had chosen a Southerner as his running-mate.  The author of that book predicted that California would be the battleground for the 1972 Presidential election, and he was not wrong in his premise.  California was a state that was predominantly Republican in Presidential contests; there was a Californian on the GOP ticket in every election from 1948 to 1984, save 1964, yet California was clearly a liberal state, socially, and had a strong moderate wing in their Republican party. 

California hasn't even been considered in play since 2000, and that was only because Bush 43, at one point, attempted a victory lap out west.  That turned out to be a mistake, and a mistake that almost cost him victory.  And along with California, New York and Texas are all one way now; Texas for the GOP, New York for the Dems.  Only Florida, of the big states, is competitive; indeed, Florida is the battleground California was supposed to be.  That fact is why Bush and Rubio have the support they do; the GOP NEEDS Florida to gain the White House.