No.
There won't be a "Trump landslide" in 2020.
Mr. Trump will win a modestly comfortable victory, and that's all.
With luck, he'll keep the states he won in 2016, and possibly pick up Minnesota and New Hampshire as well. This will improve his electoral college total, but it won't be a blowout.
Similarly, he may pick up a modest majority of the popular vote.
But a "landslide"?
No way.
Those days are over for Republicans, and they ain't comin' back.
I've posted this before, and I'll repeat and keep repeating it until November 3rd.
I would VERY MUCH ENJOY being proven 100% wrong in front of every member of this forum, but I call 'em as I see 'em, and that's how I'm calling this one.