About a century ago, the gap between the two parties was closer to 20% in any given presidential election. Today it is closer to 2%.
Many folks (including this blogger) will opine about what the Republicans' loss means for them but in a time when the political analysts have seemingly sliced the polity so neatly in two, it might simply be that with elections this close one may as well flip a coin. Never has the gap between the parties been closer (in terms of popular vote) than it has in the last handful of elections.
Here's a graph from 1912 to 2012, showing the absolute value of the gap between votes for Democrats and Republicans as a percentage of voters.