The danger in conceding that political gridlock is here to stay is that the concession is a form of acceptance, and we simply cannot accept inaction against a threat as serious and irreversible as global warming. Some contemporary issues may indeed defy bipartisan solutions, but evidence suggests that climate action and a clean energy revolution need not be among them.
If Republicans win control of the Senate, there will be the gridlock -- only much worse. It will be so bad that the American people will look back on this current Congress as "productive". Suppose, however, that independents actually control the balance of power. If they act together, they can break the gridlock.
Many Democratic women believe Clinton deserves the 2016 nomination because she was a graceful loser in 2008 and a good soldier thereafter. Nonetheless, having Clinton and Warren debate Democratic principles would be good for the party. However, the most serious problem with a Clinton-Warren battle is not gender or ideology. It's money. Many Democrats believe that having Clinton as their presidential candidate would ensure that Dems would receive millions in Wall Street donations, and enough campaign funds in general, to triumph over any likely Republican candidate.
Rather than being devoted to finding the best policy alternative, the divisions of party leave us to pursue only the second or third best alternative, usually the one that gives the least amount of credit to the other side. It is a downward spiral toward ever more narrow and inflexible partisanly limited options.