In choosing Senator Joe Biden of Delaware as his running mate, Barack Obama has acknowledged his own shortcomings while recognizing that the election he and his people thought a cakewalk a few months ago is now a battle royale along the lines of the 2000 and 2004 contests. Republicans would do well not to celebrate too much over this choice. On the surface, it may appear to be a mistake - an almost comically bad selection by Obama due to Biden's well known (and well documented) verbal gaffes. And, as Politico points out, this should worry the Obama camp: But...