The big issue here, as has been made clear, is defining just where “the center” is. It’s tough to pin that little sucker down; it keeps on moving. I don’t even see much of a continuum where centrists would exist.
Using myself (the only person I’m the best authority on), I am independent in more than just voter registration; I like to think that I make decisions based on the best available information, and I couldn’t give a fig whether my thought on a particular issue matches with Democrats, Republicans, Libertarians, Greens, or one-eyed Episcopalian kangaroos if that happens to be your kinky inclination.
As it happens, my thought tends toward Democratic and/or liberal beliefs, with important exceptions. For example, I am foursquare in favor of the 2nd Amendment. I think that regardless of whether law-abiding citizens are able to get guns or not, criminals will still find ways to do so, and the prospect of the bad guys being armed while (mostly) no one else can be is, shall we say, unappealing to me. That doesn’t, however, mean that I think every Tom, Dick, or Harry should be able to go out and buy a howitzer, assault rifle, or machine gun, or that there shouldn’t be realistic and reasonable registration laws for buying firearms. (There’s also the somewhat antiquated notion that if the revolution happens I don’t want to be without a gun. :D)
So in some ways I guess you could call that particular view centrist, because I am neither in the camp of total banning nor of everyone being armed to the teeth. But that’s only one issue among a plethora.
To accurately call oneself a centrist, I’d guess you’d have to have a majority of views that are somewhere in between liberal and conservative thought on issues. (That may sound simplistic, but it really isn’t.) Seems to me you’d have to know exactly what the liberal and conservative views on each issue were, and there would have to be a third option which is somehow between those two poles…for each issue.
Perhaps you could group moderates from both sides and call them centrists, in a loose way. Otherwise I’m not even sure of the value of the label.
Oh, yeah. Economic -4.38, Social -3.79.