Maybe one reason that a Corbyn can lead a party in Britain
The LABOR Party- Corbyn appears to have stoked the embers of what it once was.
Below a link -Interesting article historically.- If you can dodge your way through the references to internecine Communist grudges (Trotsky v. Stalin.)
The UAW and the Democratic Party - World Socialist Web Site
"...the US labor movement, virtually alone in the world, had never built a political party of its own."