Counterfactuals about the decline of the U.S. labor movement

Had the "rank and file rebellion" of the late 60s and 70s successfully taken control of a significant number of unions, would the later trajectory of U.S. politics and the labor movement have been different?

At least 4 possibilities, from leadership mattering a lot to not at all:

1. Substantial difference in political balance of 1980s, thus blunting the edge of the capital assault and retrenchment in various ways
2. Neoliberal gains could have been "slowed down," perhaps preserving some greater degree of organizational capacity for labor
3. The institutional weakness of the American labor movement was institutionally "baked in" to the form in which it coalesced by the mid-20th century. In particular, the existence of the South as a non-union region, locked in by Taft-Hartley, fatally weakened the (northern and western) labor movement.
4. The structural conditions of post-crisis world capitalism fundamentally restricted possibilities. Namely, competitive pressures in the context of world industrial over-capacity and the threat of capital mobility sharply limited the leeway for what labor could ever have won.

Some key questions

1. Was there a sufficient recovery of profits and accumulation, by say the late 80s, such that there was some "surplus" labor could have won?
2. If a more tenacious labor movement had raised the cost of the the straightforward labor-squeezing strategy adopted by many U.S. firms, what would have been their response? Would they have invested more in productivity improvements, or would they have just moved south or overseas more quickly?
3. Would the U.S. have needed German-like institutions to achieve a German-like "high road" trajectory of maintaining industrial competitiveness?