Nice idea, Carol, I agree totally. But it isn't likely to happen anytime soon.

In US politics right now, people who consider themselves to the left of the center left "liberals" call themselves progressives.

Why progressives you ask? Well, the Wellstone Democrats wanted to invoke the name of the Progressive Party of the late 19th and early 20th century populist movement of Robert LaFollette and Eugene Debs here in the Upper Midwest. The term has stuck pretty well, and so far hasn't been co-opted by the Democratic Party, despite Wellstone's use of the word. The word & the political views that accompany it these days absolutely terrifies Democrats, as is obvious from the predictable reactions of the Democrats in this thread.

To the Democratic party, there are only a few labels worse than the 'liberal' one. 'Progressive' and 'left' or 'leftist' would be two of them for sure. And when you combine those two together to get 'progressive left' well, you might just as well call yourself a communist and let the McCarthyite tactics begin.