You are right, of course. It was an electoral landslide, but most don’t think of that when they associate Reagan with a landslide win.
It wasn’t just the Reagan vote. For the first time in eons, the Republicans took the Senate. It WAS overall a masssive landslide, surpassed only by Reagan’s performance in 1984.
And, since when is a nearly 10% vote difference in a 3-way race, not a landslide.
44 states wasn’t a landslide? Wipeouts are only about five or six points.