Joe Biden vs Barack Obama
They are 2.9 apart on the PoliMap compass, a 90% match with each other on this chart.
Joe Biden (Centre-left US president) and Barack Obama (Liberal US president) are useful to compare because their public records pull toward different mixes of markets and authority. The gap of 2.9 is the straight-line distance between the two coordinates, not a moral score.
See where you land between them