Only a Moderate Democrat can win against Trump not a progressive

Why? Because most people are moderates. Some are conservatives and some are progressives but the majority are right in the middle. People aren't socialistic like in Europe here in the U.S. even now. So, a real progressive like Sanders or Warren likely cannot win. However, it might be possible to have a ticket like Biden-Warren and win against Trump. This way you would get someone black people could vote for and someone that Independents might vote for and still have someone who could take over as president in a pinch if Biden got to sick or died from old age or something. However, Trump could also drop dead at any point too if we are honest about all this, especially with his diet and general health (both physical and mental combined).