#Reuben Bolling gets it.
With the exception of a few Independents like Bernie Sanders, the political Left* in the USA uses mainstream rhetoric that harms their own causes and fights on battle grounds of the the Right’s** choosing. Trump takes full advantage of those weaknesses to promote his own brand.
* Nominally Left, really just center-right authoritarians.
** Nominally Right, really just pseudo-libertarian plutocrats.