At best, the establishment Dems have been passive observers to the catastrophic erosion of social systems over the past 50 years.
> Both parties broadly promote global US military and economic supremacy (unipolarity)
They seem to be doing a pretty bad job of preventing the rise of China as a second pole.
It doesn't mean that advocating for multipolarity isn't a political dead end in the US. Both parties are against it.
Maybe that's the goal but the execution is lacking. Seen from outside the USA it seems that the influence and the prestige of the United States are lower now than at any time in my life. The apex was any year in the 90s.
Obama started the trend. Trump accelerated it. Dealing with allies as if they were enemies doesn't help to keep a supremacy. Everybody needs friends, even big countries.