I Forgot All about This!
According to the comments at Little Green Footballs, there was a similar strike in 1934 and efforts to break that strike failed. That was, of course, during the immigration pause and we have lots more aliens around now to break strikes.
It may be that the union in question, the ILWU (which stands for I Live Without Underwear), has been coasting on its reputation for toughness ever since 1934. I'm reminded of the SF story “Bumberboom” by Avram Davidson, in which the owners of the last cannon on Earth use it to extract protection money while hiding the fact that none of them knew how to fire the thing.
Addendum: In view of some of the plagiarism scandals that have popped up recently, I suppose I should add a citation. The expansion of ILWU above was derived from an expansion of ILGWU (I Love Going Without Underwear) that appeared in a New York Magazine competition a decade or two ago.
That was far-fetched, wasn't it?