Biden would have the nomination all but wrapped up by now. Infinitely better politician than Hillary.
Yes, just look at his two previous presidential runs and compare them to Hillary's, lol. And in 2008, they were both in the same contest, right? Pretty sure she cleaned his clock.
Hillary is an infinitely better politician than Biden. It is true that Sanders is a much stronger candidate than anyone expected, and a hypothetical poll that had him trailing Clinton by ~10 points had him leading Biden by ~20 points.
However, there's a way he could be doing better. The media does not hate Biden to nearly the same degree that they hate Hillary. In fact, they kind of like him, with the media treating him as "Uncle Joe" and giving massive adoring coverage for months back in the fall. Part of that was just out of antipathy for Hillary and wanting him to run against her, but there is some personal affection for him as well. While Sanders earned much of his own support in his own right, he also no doubt massively benefitted from the media destroying Hillary's image, due to the fact that it's a zero sum game, it helped him by proxy. It's hard to quantify for sure how much of his support he would've earned without a full out media assault on his opponent though, so I'm not sure. It would probably end up being similar, but Bernie would no doubt have won Iowa.