A time traveling genie came to you and told you that voter turnout was the highest since 1900 and that the winner received over 80 million votes without telling you the identity of what happened to make voter turnout so high, the Democratic nominee or whether Trump won re-election or not.
I would've assumed either Trump did something so heinous that it caused millions more people to turnout just to vote him out of office and that the Democrat won in a virtual landslide.
Or, The economy had greatly risen in 2020 and the Democratic nominee was highly unremarkable or controversial, causing voters to break for Trump in a virtual landslide of his own.