I'm not so sure. There really was a huge anti-GOP backlash in the South post-Watergate. Even with Northwesterner Jackson as the standard bearer (and likely he would've chosen a Southerner for balance, either Carter, Govs. Wallace or Reubin Askew), I think he would've stood an excellent chance of winning and carrying a number of Southern states (my TN was going Democrat regardless, and they took out Sen. Bill Brock, too, who was painted as a dishonest Nixon crony). I also believe Jackson would've done much better in the Western states (including CA, which only went to Ford by 1.78%), enough for a win.
By all accounts, Carter should've won by a wider margin, but Ford was already rapidly closing on him at the end of the campaign (had it been held a week or two later, that might've been all that Ford needed to get Ohio, and the election, in the bag). Jackson, who was ultra-popular in Washington State and got grossly disproportionate votes as a Democrat, might've played far better overall than Carter (if anything, Carter's Southerness cost him in close races, and also Ford did better than he should've given the national climate in Northern states).
^This was Ford-Carter.
^I think with Jackson/Askew vs. Ford/Dole, it would've looked like this. You may vehemently disagree, but the only state I think Ford would've picked up under this scenario would've been Mississippi, and perhaps not even that. It would've been a landslide for the Dems, even if TX went to Ford.
I strongly disagree. No way that the RATs would near-sweep the South without a Southerner atop the ticket, even if it was Scoop-Carter or Scoop-Askew. (Which reminds me, (I forgot to list FL among the Carter states that Ford would have won against Scoop Jackson.) And without Minnesotan Walter Mondale on the RAT ticket, Ford would have carried WI (which he barely lost; that was the state that would have put Ford over the top against Carter, since he needed OH and one more) and maybe even MN (two states, BTW, in which many dovish Democrats would have stayed home had Scoop Jackson led the ticket).