Part of the success of right wingers and conservatives in getting 51% of the vote despite collectively being only 20% of all Americans is rooted in their ability to shrink the political spectrum in the minds of voters. (With help from the press they own). They have effectively misdefined moderate and the center as a position to the right of Nelson Rockefeller and to the left of the KKK. Of course those two positions are conservative and very conservative. But if moderate simply means finding a person on either side of an individual then Karl Marx is a left winger, Paul Wellstone is a centrist, and Ted Kennedy is a right wing conservative.
What the Democratic Party has failed to understand is that the ideology that defines the center wins this battle wins the war. There are tens of millions of voters who will "go with the flow." Go with the flow is simply voting for what's being called moderate even if the label is incorrect. Give people a poll and the choice or choices in the middle will almost always be overrepresented.
Therefore, it is our responsibility to redefine (or properly define) what the middle is. If you can have the center defined as Anthony Kennedy (who is to the Right of Nixon), we lose. However, if we can have the center defined as halfway between Karl Marx and Hillary Clinton (which it almost is), we win. We can do that by creating a list of 8-12 labels and positioning liberalism right in the center. (Where it really is). We can create a frame in which conservatism gets pushed so far out of the mainstream that it never gets perceived as a viable option again.
So although I believe the political spectrum is mostly circular and yes people's views can be diverse, we need to implement, for simplicity purposes, a flat line paradigm and then cite these labels over and over and over again. From left to right that line would be Communist, Left Wing, Socialist, Progressive, Moderate/Centrist, Liberal, Libertarian, Conservative, and Right Wing.
Note that if you fall for the false media frame of liberal, moderate, and conservative, then libertarian becomes moderate and half the political spectrum doesn't even appear in the frame. And that's exactly what the right wing wants.