If the membership doesn't tell the leadership chain at all levels that the scope garage sale is over forever, it won't matter what alphabet group represents anyone, as in either case the career will be sold down the river for one time cookies for whoever is "in range" of retirement or otherwise insulated from today's round of scope sales.
DPA is running, in part, on the scope sale failures under ALPA's watch. Great. I hope that generates a lot of attention. But what would DPA really do if they win, and the same membership votes in the same scope sales for the same one time cookies? Will they put in the bylaws no scope sales (and in fact, scope reclamation, however slowly) will be voted in, regardless of membership wishes? I doubt they will promise that.
Now if the anti-scope sale rhetoric is backed up by the DPA in bylaws and/or specific campaign platforms and the like, and THAT is what causes DPA to oust ALPA, then great. But if that were the case, we would already have the same groundswell support for measured scope reclamation within the existing structure anyway.
IMHO the tie breaker issue just might be ALPA's stance (as well as their muscle on Capital Hill) on the potential gutting of the international relief pilots if the new 2/3 crew scheme replaces the current 3/4 crews on deep international ETOPS flying. There needs to be safety improvements at the regional level where work rules are FAR's only (to a large extent) but that must NOT be paid for by reducing safety on long haul ETOPS and gutting thousands of widebody FO positions and/or expanding the lower end of outsourcing (or even tolerating the current level for that matter).
What is right, not who is right. We will see what DPA offers and how ALPA responds. But in either case it all comes down to membership resolve and resistance to myopic greed to stop the selling of tomorrow's career for today's cookie.