Breckinridge, and Bell, not really.
Douglas is an up in the air thing since the deep south hated him.
I think it's very unlikely that Douglas would be elected (Illinois was the only state with a Douglasite majority in its House delegation) but if he were I am reasonably sure the South would
not secede. Secession was actually a close enough thing even with Lincoln, as I explain at
https://www.alternatehistory.com/fo...ncoln-becomes-president.424396/#post-15481060 Even the most extreme South Carolinian would realize that their state would be totally isolated if they used Douglas's election as an occasion for secession. True, Douglas did poorly in the Deep South, but still he got 15 percent of the vote in both Alabama and Louisiana, and 11 percent in Georgia; and many of the Bell voters in the South would have no particular objection to Douglas (indeed, even some moderate Breckinridge supporters, like Andrew Johnson, would have no problem with Douglas). The situation differs radically from that of Lincoln, who got virtually no votes in the slave states apart from Delaware, St. Louis and a few German counties of Missouri, and the Wheeling Panhandle of Virginia.
Indeed, there really seems little sense in acquiescing in a Bell presidency but not a Douglas one. Bell, like Douglas, had opposed the Lecompton Constitution; and unlike Douglas, he had opposed the Kansas-Nebraska bill.