I have an argument with a friend where I support free college, Medicare4All, Green New Deal etc. & she tells me we need an "incremental approach;" that such things are "too far left." I tell her they're centrist in Europe.She says "We're not Europe." I bang my head against a wall

Centrists do tend to win elections. There are lots of moderates in the Democratic party. Too far left and you lose them and the election . They are more reliable voters. What progressive ever won the Presidency? FDR? That is pretty far back and he had 12 years of a Dem congress.