I now see Norman Thomas as indeed a liberal, but as a real, old-fashioned, unreconstructed liberal who believes in freedom and justice for everybody.
There isn't much point arguing about the word "libertarian." It would make about as much sense to argue with an unreconstructed Stalinist about the word "democracy" recall that they called what they'd constructed "peoples' democracies." The weird offshoot of ultra-right individualist anarchism that is called "libertarian" here happens to amount to advocacy of perhaps the worst kind of imaginable tyranny, namely unaccountable private tyranny. If they want to call that "libertarian," fine; after all, Stalin called his system "democratic." But why bother arguing about it?