I wouldn't say massive margins. And they didn't always win it.

  Gore    (D) got 52.1% in 2000, and lost.
  GWB     (R) got 50.7% in 2004, and won.
  Obama   (D) got 52.9% in 2008, and won.
  Obama   (D) got 51.1% in 2012, and won.
  Clinton (D) got 53.5% in 2016, and lost.
  Biden   (D) got 51.3% in 2020, and won.

George Bush won the popular vote in 2004, just barely. Otherwise the point stands - especially for 2016, where the popular vote for the "winner" Donald Trump was only 46%, a margin of about 3 million people. It was the third most disenfranchising election in American history, and the others were in the 1800s.

https://en.wikipedia.org/wiki/List_of_United_States_presiden...