Of course there's also a lot of True Leftist hate for Wilson because he essentially killed any hope of there ever being an American labor party by aligning the Democrats with organized trade unions by, among other things, pushing through Congress the "Magna Carta" of the American labor movement.
Odd that there were continued attempts to build a labor party (some actually led by labor bureaucrats themselves!) after Wilson, if what you're asserting is true. The early 1920s saw the American Federation of Labor and Railway Brotherhoods get very close to endorsing an independent Farmer-Labor Party, but this was jettisoned by the insane anti-communist mood set in motion by Wilson and the Democratic Party.
Likewise, when the CIO moved toward the direction of a Labor Party in the 1930s, it was stopped by the pro-FDR Communist Party USA.