As the saying goes, birds of a feather flock together.
Via Trevor Loudon:
I have long contended that the US’s largest and most militant labor organization the Service Employees International Union, is allied to, or subordinate to the country’s largest Marxist organization — Democratic Socialists of America.
Here is proof of this connection, from the latest edition of DSA’s Democratic Left, Winter 2011/2012, page 11.