Politicians in the US track the median very closely. If 30% of voters believe something, close to 0% of politicians will. If 70% of voters believe something, close to 100% of politicians will. We saw this most clearly with gay marriage - Obama and most of the Democratic Party flipped their positions right when the poll numbers passed 50%.

It doesn't really matter. Even if you have a Pew poll saying that a good amount of voters believes that “prevent people from getting rich” or “end all economic inequality”- those are just vague sentiments and not real policy. There are no mainstream American politicians in either party with any proposals that even remotely resemble that sort of idea.