When it comes to moving to the center, that time honored tradition of presidential candidates once they secure the nomination, it should have been obvious to Obama's team and Democratic operatives and the base, that he would have a far tougher time of it. Obama's primary victory came off the notion, whether true or not, that he would be mroe loyal to the liberal base than Hillary Clinton, whose personal politics and that of her husband were far more centrist that the looney left was willing to concede.
Now in an effort to start appealing to the critical center of the political spectrum, Obama has to move toward the right, but it appears that his campaign has no real plan to gracefully do that. So we get silly comments like the whole English/Spanish stupidity and foriegn policy gaffs. Ultimately, Obama is just as likely to lose as many far left voters as he is likely to gain independents, not a winning formula.
On the other hand, John McCain has been sitting on the political fence in the center of the country for so long, it is part of his anatomy. Not exactly endearing to conservatives, but at least he is trying to appeal to them.