It would have been a competitive race and certainly no landslide. A coalition consisting of the conservative Republican base that Bush abandoned, the Perot-ites, and midwestern Reagan Democrats (a group that Buchanan, with his views on trade and cultural issues, would have been well positioned to keep in the GOP fold) would have been very formidable. Clinton would have started the general election campaign with a big lead but an energetic GOP campaign and an impressive showing by Buchanan in the debates would have led to a rapid narrowing in the polls.
Clinton wins but Buchanan makes him sweat for it; Missouri, Pennsylvania, and Michigan are all decided by fewer than five points.