I haven't forgotten Jackson. The only thing candidacies by both Clinton and Gore would do would be to make sure that Jackson does even better in the South than in OTL (for example, he will carry North Carolina, which he very narrowly lost to Gore in OTL).
https://en.wikipedia.org/wiki/Democratic_Party_presidential_primaries,_1988
As for Gore in 1988 being much more conservative than Clinton n 1992, please remember Sister Souljah and Clinton's making a point of returning to Arkansas to oversee Ricky Ray Rector's execution...
https://en.wikipedia.org/wiki/Ricky_Ray_Rector
Yes, there were differences between Clinton and Gore, but fundamentally both of them ran as southern "New Democrats." Of course neither could win with the South alone, but in both cases the South was their initial base. Gore never got the breakthrough in the North that he wanted in 1988. But neither would Clinton have
in 1988 especially with Gore as competition. It took Dukakis' loss to convince many northern Democrats that only a southern New Democrat was electable (which ironically was probably not true in 1992!).