Earlier quoted context omitted.
I can’t speak for the person you’re asking, but Tulsi Gabbard is representative of what I see as the rational middle.
The only way you can see Tulsi as the "middle" is because the overton window has slammed so far right. In a rational society, Biden and Obama would be considered middle and AOC/Bernie left.
The democrats are a center right party. The republicans are at this point, a far right party. It has been a deliberate strategy of the far right to paint the center as "socialism" (which a lot of Americans seem to mistake for communism...), because it makes their ideology seem less extreme. A lot of Americans have fallen for that nonsense, unfortunately. Definitions and framing and perspective matters a lot.