[Right now,] workers typically become union members only when unions gain majority support at a particular workplace. This makes the union the exclusive representative of those workers for purposes of collective bargaining. Getting to majority status… is a struggle. The law barely punishes employers who violate it, and the success of the union drive is typically determined by the level of employer resistance. Unions usually abandon workers who are unsuccessful in their fight to achieve majority status, and they are uninterested in workers who have no plausible near-term chance of such success.That seems spot on, or at least a step in a spot-on direction. As mentioned before, it seems very unlikely that either organizing or political action will boost labor density by a significant amount, and the latest intra-labor feuding has a bit of a more-heat-than-light quality to it, in that respect at least. Taking the historical view, it's usually been new innovations, of just the sort Freeman and Rogers are discussing, that have lead to "spurts" in organizing. Now if a split in the AFL-CIO can make it more likely that innovations of this sort will appear—competition being the mother of invention and whatnot—then so much the better.
Under open-source unionism, by contrast, unions would welcome members even before they achieved majority status, and stick with them as they fought for it--maybe for a very long time. These "pre-majority" workers would presumably pay reduced dues in the absence of the benefits of collective bargaining, but would otherwise be normal union members. They would gain some of the bread-and-butter benefits of traditional unionism--advice and support on their legal rights, bargaining over wages and working conditions if feasible, protection of pension holdings, political representation, career guidance, access to training and so on. And even in minority positions, they might gain a collective contract for union members, or grow to the point of being able to force a wall-to-wall agreement for all workers in the unit. … Joining the labor movement would be something you did for a long time, not just an organizational relationship you entered into with a third party upon taking some particular job, to expire when that job expired or changed.