It is often said that every argument on the internet eventually boils down to a Hitler/Nazi analogy if allowed to run its course. Certainly we all have witnessed Godwin's Law in action or perhaps even fulfilled its predictions ourselves. It's time to add a corollary – perhaps named something catchy like "Gin and Tacos Law" – for discussions about presidential elections. As discussions and arguments continue, the odds of Supreme Court appointments being used to rationalize supporting an obviously uninspiring candidate approach 1.
Every discussion about the tepid vat of weaksauce that has been Obama's first term (compared to his 2008 campaign rhetoric and, unfairly, to expectations projected onto him) effectively ends with something about Alito, Roberts, Thomas, and Scalia followed by warnings about who President Romney-Santorum-Gingrich would appoint. Republicans are now engaging in the same logic to talk themselves into supporting a nominee about whom they are clearly ambivalent at the very best. We can't let that Kenyan usurper appoint another one of his Marxist academic buddies, so I guess it's time to suck it up and vote for the automaton.
The problem with this argument is not that it is wrong. It's quite obviously valid; the Supreme Court is important and the president has few restraints on who he can appoint. The problem is that resorting to the "We have to vote for Obama because Romney will appoint lunatics to the Court" argument is a glaring indication that your candidate is in trouble. It's the kind of argument of last resort that arises only when all of the arguments that would imply actual enthusiasm about the candidates have been exhaustive and, in most cases, contradicted.
I'm a big believer in the idea that presidential elections are decided by turnout. In any given election the number of persuadable ("undecided") voters is comparatively small. The outcome is more likely determined by the turnout differential between the most likely supporters of each party. In 2008, for example, Barack Obama blew McCain away because a lot of people got really, really excited about his candidacy and drove turnout to its highest level since the Sixties. Conversely, McCain was unpalatable from the beginning to some conservatives and by late October 2008 his campaign was such a debacle that even the most optimistic Republican knew what was coming.
What happens when nobody's enthusiastic on either side? Well, you get elections like 1996 or 2000, and they're usually extremely close. Turning out the base takes on additional importance in close elections, so The Faithful are rallied with every rhetorical tool at the campaign professionals' disposal. And nothing says desperation and lack of interest quite as clearly as "Well Ginsburg's probably gonna die soon, so get excited about Mitt!"
It's obviously incorrect to say that Obama has no accomplishments on which to run, but it is not a good sign that the liberal base is being fired up with hypotheticals – warnings about Mitt Romney's potential Court appointments and Obama's recent endorsement of a position on an issue that, if re-elected, he will never actually vote on. For better or worse, 2008 saw quite a bit of the kind of I Love This Guy, He's Gonna Change the Country enthusiasm that Obama's campaign is going to have to do without this time around. Clearly Romney will be going without it as well since everything about him just screams "default candidate".
So by all means, keep bringing up the Supreme Court. It's a valid point for either candidate. Be aware, though, that in doing so you're tacitly admitting that you've punted on generating actual enthusiasm for the candidate – unless, of course, you envision an electorate full of people who say things like, "Fuck yeah! We better get out and vote for Obama in case there might be a Supreme Court vacancy!" I'm a tad skeptical about how many such voters exist.