Joe Biden loves Barack Obama. His best friend. I believe that. It's also a bit weird, but I'll let that go. He also truly believes that the reason that Republicans wouldn't work with him, the reason Republicans were mean to him, was because he was black. It is true that the election of a black president caused brains to snap a bit more than usual than whenever a Democrat is elected president, but only a little bit. I remember the Clinton years. Neoliberal sellout Jimmy Carter is history's greatest monster. They weren't elected, but I remember the Gore and Kerry campaigns.
The Republican party, from Mitch McConnell on down to that nice old racist at the diner, does not believe that anyone with a D after their name has a right to be president, and much of Official Washington - even the supposedly nonaligned part - basically agrees with them. Bill Clinton was "not my president" and the day after election day 2008 every pundit rushed to their computers and to the TV studios to reassure us that what Barack Obama's election proves, most importantly, is that America Is A Center Right Nation. Miraculously, the American People are right where Official Washington is! Amazing.
Joe Biden believes that he is the only candidate who will be treated "fairly," that his good friends, those fine people in the Republican party, wouldn't possibly be mean to kindly old white Uncle Joe.
The presidency is a big prize and Republicans play to win. I'm not always sure what game Democrats are playing, but they should at least understand the game that Republicans are.