As a labor historian, what’s your take on the “One Big Union”?

That’s a hard question to answer. The IWW, which occupies a mythic position within labor history/labor studies for a mixture of romantic/ideological/aesthetic reasons, had many strengths and weaknesses. 

In the plus column: a focus on industrial rather than craft unionism, a belief in interracial and immigrant organizing, innovative protest strategies (esp. around free speech), and some of the best cultural/educational organizing ever.

In the minus column, two huge deficits. First, the IWW had a profound objection to building permanent organizations, which made it impossible for them to actually build on any victories or meaningfully organize the working class over time. Second, the IWW also had an insolvable split over whether to engage in politics at all, which led a lot of IWW activists to engage in ultimately pointless and counterproductive sabotage campaigns and meant that the IWW wasn’t really able to shift public policy in a more progressive direction.