The current United States is now a politically moderate nation that leans slightly conservative. In the buzzword addled opeds of the post 2008 election U.S., this means we are a "center right nation". But before the Republicans cheer and the Democrats cry foul, it is instructive to first consider the bait and switch pulled by the righty pundits.
Currently, a typical American media consumer would equate "left" with "Democrat" and "right" with "Republican". As a relative measure, I certainly agree. If this is the frame of reference, then it is patently absurd to claim that the United States is a "center-right nation". This is tantamount to saying that the United States is a "moderate Republican nation". Clearly it isn't, at least if you measure that in terms of the U.S. House and Senate, the U.S. Presidency, the 50 state governors, and the state legislatures. Democrats control a majority of each of those categories. If anything, by this criteria, we are a center-left nation.
But, in a more general sense (globally as well as historically), it is more accurate to describe the political sensibilities of the current Democratic establishment in general (not just the Democratic wing of the Democratic party) as very centrist, at least in a global sense. However, rather than merely being moderate and leaning left, I'd actually make the claim that Democrats are moderate and lean slightly right.
On the other side of the aisle, even the moderate Republicans are firmly in the right category, while the right wing of the Republican party live somewhere where "centrist" and "moderate" are dirty words. Ask any European friend and they'll tell you that by the standards of Europe that the U.S. Democrats are by no means on the left fringe. On the contrary, the most frequent comparison I get are to European center right parties.
However, don't allow this little fact be used as a bludgeon by the far right pundits to score points in sophistry. In my book, the correct progressive response involves a little verbal jiujitsu:
MSM Pundit: "The U.S. is a center right nation!"
Progressive: "How true, how true! And Democrats are the center-right party. In 2008, the American people rejected the premise that we should be governed from the far right (again). It is time to finally try out being governed from the center-right. I'm not satisfied yet, but we're definitely going in the right direction!"