Two points:
1) I wish Never would never post in my threads like he has repeatedly said he would not.
2) Didn't the GOP also bash all the polls showing Obama up months before the election?
I don't see why everyone thinks that Democrats are only in a good position because of Hillary. Does anyone really think their electoral advantage is dependent upon Hillary specifically?
Many are disappointed because Barack Obama has failed to deliver even more change to their liking. In 2016 someone can pick up much of the vote of people who did not get all that they wanted because the Republicans made such impossible. The Republican nominee, unless running to the left of someone like Hillary Clinton on that (extremely unlikely) will not win voters who think that Obama hasn't achieved enough.
So far Hillary Clinton is the only one who seems able to win those voters. I have no idea who would outdo her at that. But this can be said: both the Corporate wing of the GOP and the Tea Party wing offend the sensibilities and economic interests of so much of America that they have a distinct disadvantage built in that they will have to pick up nearly every persuadable vote to win.
Biden has had plenty of chances to win the Democratic nomination, and he did not get it. He had immeasurable weaknesses as a potential nominee in his 50s and those weaknesses have surly not disappeared.
About 240 electoral votes belong to States and DC that have not voted for a Republican nominee for President since at least 1988.
There are alternative explanations. He disappoints some people who are to the left of the mainstream of the Democratic Party who will still vote for just about any Democrat for President. FoX News is hammering everything the President does. If it had a 'Style' or 'Fashion' segment the analysts would attack the President for his sartorial choices. In November 2016 that will no longer matter.