Amid the breathless speculation as to whether Vice President Biden will get into the Democratic presidential race -- and, if not Biden, then who else? -- there's one name that's consistently overlooked: Jerry Brown.

Yes, that Jerry Brown. The one who was governor of California at age 36 way back in 1974. The one who ran for president in 1976, 1980 and 1992. The one whose eccentricities earned him the name "Governor Moonbeam." And the one who got elected governor, again, in 2010 at the age of 72 and reelection at 76 (!) last year.

Sound crazy? It's not. Really.

First, consider what Brown has said about the 2016 race -- and the problems that Hillary Clinton has encountered in it. Here's Brown in an interview this week with CNN's Wolf Blitzer in which Blitzer pressed Brown on why he has yet to endorse a candidate in the presidential race:

I would say, though, it is early. You could have a lot of big surprises, a lot of action between now and the first Iowa caucus and the New Hampshire primary. A lot's going to happen in the Republican primary, and I think some things could happen on the Democratic side as well.

That comes after Brown told "Meet the Press" host Chuck Todd over the summer that Clinton's e-mail issue was “almost like a vampire, she’s going to have to find a stake and put it right through the heart of these e-mails.”

So ... if you are the Clinton folks, who are doing everything they can to reassure donors and the political establishment that everything is TOTALLY fine, those aren't quotes that makes you feel warm and fuzzy inside.

Then remember that despite the fact that Brown is playing nicey-nicey with the Clintons at the moment, there isn't much love lost there. When Brown ran for president in 1992, he stayed in the race all the way through the June California primary -- where he lost to Bill Clinton by only seven points. The Clinton team made no secret of their unhappiness about how long Brown lingered.

Then there was the moment in a March 1992 debate where Brown savaged Clinton over his and his wife's ties to the Rose Law Firm. "He is funneling money to his wife's law firm for state business," said Brown of Bill Clinton. "It's the kind of conflict of interest that's incompatible with the kind of public servant we expect." If you think the Clintons -- or Brown -- has forgotten about that accusation, you don't understand how politics works.

Brown is also currently the governor of the largest state in the country -- and one that is chock-full of Democratic voters and, maybe more importantly, Democratic donors. Brown is quite popular in the state -- 52 percent approval to 27 percent disapproval in a May Public Policy Institute of California survey -- and has overseen an economic recovery in the state that many people thought was impossible when he took over the office in 2011.

Plus, Brown is stylistically a striking contrast with Clinton. While he remains somewhat eccentric, he is without question charismatic and the sort of straight-talker that the public seems to be clamoring for. (If you need evidence of Brown's straight-talking nature, please scroll up and read what he had to say about Clinton's e-mail problems.) Michael Kinsley, making the case for Brown in Vanity Fair earlier this week, described Brown's appeal this way:

All that New Age stuff that seemed so weird when Brown ran for president the first time (in 1976) is still part of his repertoire. But he’d be helped if he ran by the extent to which yoga and brown rice and so on have become part of American culture. Jerry Brown hasn’t gone mainstream (or at least not much), but mainstream has gone Jerry Brown.

There are, obviously, hurdles to Brown running -- most notably the fact that he is 77 years old. If he was elected president in 2016, Brown would be the oldest person ever to hold the office -- by a lot. (The oldest president, Ronald Reagan, was 74 ... when he was sworn in for his second term.) Then there is the fact that California is currently in the midst of a record drought and severe wildfires; considering a presidential bid against that backdrop might look opportunistic at best and callous at worst.

Even considering those factors, Brown's case against Clinton is as serious as anyone this side of Biden. And the threat he would pose to her is not to be dismissed.

Look: Brown probably won't do it. But, can you rule anything out for a guy who was elected governor of a state in the 1970s and the 2010s? I say no.