LOL Trump tried to be a populist and you are right that simple slogans and the electoral college gerrymander got him over the line in 2016, however he was never truly popular.
He won the presidency without winning the popular vote given Hillary Clinton beat him on that score. Trump also did not increase his popularity broadly across the USA as time passed during his term. The average of polls always had Trump with less than 50% approval during his whole term, whereas Presidents Clinton and Obama and Bush did actually achieve majority support regularly during their terms. Furthermore, Clinton, Obama and Bush each won a second term whereas Trump lost in disgrace.
Trump was a con man who managed to con some dis-affected people but was never able to command the support of a majority. He was a lying Disallowed merchant and megalomaniac who promised the world but instead incited division and oversaw the death of over 500,000 Americans as his legacy. He faces multiple court actions which will likely wear him down given his age.
