They were aware not only of their potential collective power, and not only of their oppression - but they were aware they weren't alone. Many of the leaders and rank and file members were politically on the left. You could call some of them communists, some of them socialists, some of the members of the IWW - a variety of different traditions suspicious of capitalism, and one of the reasons was they understood that employers, time and again - and still to this day, play workers off each other race, ethnicity and nationalism.