There are basically two ways of winning a nomination: You're either the establishment candidate or the insurgent. Joe Biden is neither. Hillary Clinton is clearly the establishment candidate. She might lose, but she's not going to bow out and leave the field to Biden. The Clintons own half of Washington. You can't out-establishment the people who built the establishment.
So, is Joe Biden an insurgent? Of course not. What grassroots support does he have? Does anyone know of any real people clamoring for Biden to get into the race? If you think you do, you live in Washington and you don't know any real people.
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Why are people excited about Bernie Sanders? Because they know where he stands on the issues and they know that he has fought for those positions his whole life. What has Biden fought for his whole life? Amtrak?
Don't get me wrong, Biden has been great on many issues, including fighting for women's rights and reasonable regulations on guns. Still, he's caught in a no-man's land where no one is all that excited by him — the grassroots or the establishment.
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Let's get real. The only reason we're having this conversation is because Biden would be the replacement candidate for the establishment if they perceive Hillary as too damaged. When people perceive you as the pinch hitter for another candidate, you're not in good shape.
Now there is another guy who is in the middle but actually does have significant support from both sides of this equation. He was also a vice president but is beloved by a sizable portion of the grassroots. He could rally both sides as a candidate who is clearly progressive enough and established enough for a presidential run.
Al Gore for president? Now, that would change the climate of this election.
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Commentary by Cenk Uygur, the host and founder of online news program The Young Turks and CEO of the TYT Network, which generates more than 90 million views per month across a range of digital platforms. Uygur has previously hosted shows on MSNBC and Current TV. Follow him on Twitter @cenkuygur.