By Alexander Burns of the New York Times
These voters may not represent a controlling faction in the Democratic Party, at least not yet. But they are increasingly rattling primary elections around the country, and they promise to grow as a disruptive force in national elections as younger voters reject the traditional boundary lines of Democratic politics.
Energized to take on President Trump, these voters are also seeking to remake their own party as a ferocious — and ferociously liberal — opposition force. And many appear as focused on forcing progressive policies into the midterm debate as they are on defeating Republicans.