I refuse to believe that politics must be about ideology. Most politics and policy deals with reality and as such ought to be evidence-based. As it happens, there is usually a party that sides with reality more closely. So why was this election critical?
There are good reasons why the US election is an international issue most importantly globalisation, but we also should emphasize with the American people. Of course, Barack Obama is not a good president, far from it, but the only realistic alternative was cataclysmic.Therefore the election can be considered a small win for science over noise, which was perfectly predicted in advance by the famous poll aggregator Nate Silver.
To understand why, let's look at science and health policy: With the Republican slash and burn approach to the budget, funding for the National Institute of health (NIH) and National Institute of Aging (NIA) would be in jeopardy. We already know funding for the NIH wasn't exactly rosy during the last Republican administration.
However, research may be crippled by other means too. Remember that it was the Republican George W. Bush who appointed and listened to bioethicists like Leon Kass, who is not only anti-abortion and anti-stem cell research, but also firmly opposed to life extension. With such monstrous friends who needs enemies? I doubt a republican president would be less radical today, given the strong grip the Tea Party has on the GOP.
And this is not offset by any benefits to the free market, i.e. pharma companies, that I know of.
Tens of thousands die due to a lack of insurance each year, and it took a Democrat to broaden coverage against fierce opposition. Colour me unimpressed, Republicans.
On the other hand, if a Supreme Court of the United States (SCOTUS) appointee leads to an overturn of Roe v. Wade, allowing bans on abortion, tens, probably hundreds, of thousands will die as an (in)direct consequence of medical complications and of being born into dysfunctional families.
A SCOTUS and president that kills Roe v. Wade may enable the teaching of creationism in school, even if it is just by a back-door.
The Republicans continue to deny the scientific fact of AGW and ecological problems, and under such an administration reckless exploitation of the environment will continue to erode the long-term growth potential of the US.
Republican economic policy paints a picture just as bleak:
While Obama generally embraces very successful new Keynesian economics, that saved (or could have saved) millions of jobs. His opponents call for pernicious tax cuts for the rich, severe spending cuts in a depressed economy, undermine Social Security, continued deregulation, etc., showing their disdain for the poor.
The republican war mongers brought us two unnecessary wars that cost trillions, which could have been spent on - oh, I don't know - education, research, biogerontology and the global fight against poverty. Foreign policy is one of the key the reasons why Republican politicians are despised in most developed countries.
The Republican track record on social issues is even more horrifying: jingoism, homophobia, racism, misogyny ("the war on women"), prudery and radical evangelical Christianity are rampant in their party from the bottom rungs to the top - with few exceptions.
Disaster has been averted, for now.