Wouldn't it be nice to be able to do a real scientific experiment. We need three earths, all starting from the same state as of today. On one earth we elect Romney. On one we elect Obama. And on the third we elect a completely random person (a kind of control!) Now we observe the evolution of the planets over the next four years. What would you hypothesize the outcomes?
Many people are voting for Obama as the least worst - do the least damage - candidate. Many are voting for Romney as the least likely to go socialist candidate who will restore America to her exceptionalist roots. All of these voters have very different visions about how things will unfold under the two different scenarios (no on thinks about the third). But all of those "hypotheses" are based on completely incorrect assumptions about the state of the world and what is "possible" in the future.
The reality is that the forces at play that will shape our world in the years to come are already too powerful and too advanced for either real candidate, or even the control president, to have any significant impact on what is unfolding. We are inexorably running down on net energy to do useful work. The climate is now past the point of no return in terms of devastating change. From here out you will not be able to detect the difference between what either a president Obama or president Romney does for better or worse. Neither has a clue what is causing our global economy to collapse, so neither has any idea about what to do to lessen the pain, let alone reverse the course. We might as well have elected an arbitrary person to the job.
Of course, because both are blind, either will do damage as they attempt to 'fix' things according to their ideologies and beliefs about how the world works. Obama has already done irreparable damage to the real economy in allowing the financial world to continue to rob us blind. That will just get worse. And his belief that somehow, investment in alternative energies could make things better, if not turn things around (you know - green jobs, and all), is uninformed with scientific reality, even though his Sec. of energy is a Nobel physicist! This damage is insidious because on the surface it looks like attempts to preserve normalcy. It even appears, to the naive, that Obama's policies are working. The jobs situation looks a bit better (but look deeper, for example at the actual wages being earned by those new job fillers). But I suspect the current seeming improvement in economic numbers will soon evaporate after the election. If Obama wins, in fact, we could see a very rapid fall into an earnest recession/depression as the Republicans pull a scorched earth move and push us over the so-called fiscal cliff.
For his part, Romney will do damage just by not having any clues about what to do at all. He is driven by ideology (pushed, for example by the Koch brothers) that is the very set of beliefs that drove us to the point we are at now. And if he wins I'm betting there will be a significant Democratic resistance the mirrors what the Republicans have done in the Senate while Obama has served. Stalemate.
And if you are worried about the effect on the Supreme Court of a Romney presidency, don't. First there is really no reason to believe Obama wouldn't put someone in place that isn't already owned by corporatocracy and Wall Street. He might, but his lack of any significant action against Citizens United suggests that he too is a wholly owned subsidiary of business. He believes that capitalism is the answer to the problems after all. Second, the time scale over which any effect of a judge appointment would be noticeable is too long compared to the time we actually have before the wheels come off the track. If people today are worried about what the court will do re: things like abortion rights or gay marriage, they will soon be forgetting those issues as the real problems of getting adequate food and other resources start to dominate the scene. The Supreme Court will become as irrelevant as is the Congress and the presidency now.
My hypothesis is that observed from a certain distance you will not be able to tell any difference between the three planets. There is simply nothing that any human can do to reverse or even significantly slow down the innevitable contraction of the global economy and the impacts of severe weather events. And those are going to make much more of a difference in our lives than anything else.