It shouldn't be because it's what he's said all along. Again - you might not like it, but he made it abundantly transparent.

1) "Sore loser" - not a great message for him to send to anyone if he lost within a party and then said "Well, I used your infrastructure to help elevate myself - fuck off and I'm running as an independent."

2) The spoiler effect. He's repeatedly said stopping Donald Trump is a priority. I'm not even grouping someone like Ralph Nader into this category. Bernie has a real following and could take enough of the vote to make a difference in the electoral college. Maybe not Ross Perot level - just because Perot was a billionaire - but enough.

3) It's a stressful and exhausting job to run for president within a major party and getting to use their infrastructure. Do you know why we've been able to knock on doors and make phone calls using data? Because we're been provided with data on these homes of voters and the campaign can decide how we target them.

You lose all of that with an independent candidacy.

4) Logistically running for office as an independent is a million times harder than the logistics to run within a major party. You need billions of dollars to run a credible 3rd party campaign - which is why Gary Johnson is trying to court Republican donors and why only someone like Ross Perot or Bloomberg could run a legitimate 3rd party candidacy.

His supporters did an amazing job in this primary - and hope they will continue to through tonight to deliver a big win in CA. But the problem is they needed to step up more and in greater number given the mountain he was facing with the most powerful political organization in American history. I said it from day one - Bernie needed a revolution because in a conventional campaign Hillary would win every time.