[helaoban]

Does the term landslide have a widely accepted definition? One definition could be winning every single swing state, which Trump did.

I think you also have to factor in the degree of political polarization today, and in particular Trump's polarizing nature, which means that there is smaller pool of "effectively independent" voters to fight over. So 1% today is worth more than %1 in 1984. These, are of course, not particularly quantifiable measures.

The point is taken tough, "comprehensive victory" would have been the more appropriate description.