On Tuesday 5 Nov 2024 Dummkopf Trumpf won a plurality-- not a majority-- of the popular vote at 49.8%.
Only 64.1% of eligible voters turned out that day, a decrease of 2.5 percentage points from 3 Nov 2020 when 66.6% of eligible voters turned out. This was an increase of 6.5 percentage points from 2016.
As JPW points out, Trumpf didn't win in 2024, rather Dems lost.
Hillary Clinton proved a woman could be POTUS, Barack Obama proved a man of color of could be POTUS, so race and misogyny can be ruled out in Kamala's 2024 loss. And her VPOTUS pick couldn't have been more white and status quo than gun-owning, animal advocate, military veteran, football coach Minnesota Governor Tim Walz.
Democrats vote for policy, not personality. Republicans seem to vote for personality, not policy.
Too bad USAG Merrick Garland sat on the explosive Jeffrey Epstein files from 21 Jan 2021 to 19 Jan 2025. SC Jack Smith could have continued with his dual track investigation into Dummkopf Trumpf (6 Jan insurrection and hoarding classified documents) while an ordinary AUSA from SDNY could have put together a damning indictment and conviction of a certain orange-hued wealthy pedophile.

Biden was too decrepit and senile for the presidency. He should have never been elected 2020.
Most Democrats understood this, especially towards the end when he was basically forced to cede his campaign to Harris.
But,
Republicans, who complained endlessly about Biden's senility, went and elected their own crazy and senile geriatric as soon as they got the chance. And now their guy is suffering obvious mental decline.
Tools like Belldinger et al. have no justification whatsoever to complain about Biden with respect to competency. But they will continue to do so anyway because they are hypocrites.