in the u.s., i think this explains most elections since 1980 (note that, in the following text, the descriptions of the candidates are not meant to be factually accurate, but represent what, i imagine, the average u.s. voter thought about them)

reagan won against carter because a friendly-looking guy who appeals to patriotism sounds better to conservative voters (once again: NOT the same thing as "conservatives", but specifically voters that don't care about larger politics aside from some pet issues and a desire to not be bothered) than a pie-in-the-sky democrat who screwed up the economy and couldn't negotiate the iran hostage crisis

then reagan won against mondale because the economy was in a good shape and mondale was seen as too radical on a bunch of issues

then bush sr. won against dukakis because the economy still looked good, bush was reagan's veep, and dukakis got screwed up with a silly-looking tank photo and the willie horton stuff

then bush sr. lost against bill clinton because he promised "no new taxes", only to raise taxes

then bill clinton won against bob dole because the economy was in a good shape and, for once, had a surplus instead of deficit, and running on a policy of further tax cuts and reaganomics doesn't make sense if the purported goals of reaganomics are already there

then al gore narrowly lost to bush jr. because of the florida shenanigans (i assumed that al gore would be considered a climate change nut by then, but apparently that happened later)

then bush won against kerry because bush was still enjoying his post-9/11 patriotic popularity boom, and it was a bad time to be perceived as anti-military back then

then obama won against bush jr. because people were really tired of bush jr., like really tired, to an extent that has only been succeeded by donald trump

and won against mitt romney because the economy was recovering and romney came across as a mormon weirdo who would disregard any u.s. american who was too poor to pay income taxes ("the 47%")

then hillary clinton lost against donald trump because apparently being a female candidate gives you a double damage from all scandal-type attacks (seriously, the benghazi stuff was litigated so incessantly in a way that i don't think any male candidate ever had to suffer) and the pop-culture image of the democrats' message has shifted from "we just want you to relax and do whatever" to "we want you to feel shame for being white or a man" (once again, not accurate, but the religious right has lost a lot of its moral authority and the fact that donald trump was a sex pervert meant that he came across as less involved in the culture war in comparison)

then donald trump lost against biden because he messed up the economy big-time, his covid policies were a disgrace, and it turns out that just because trump specifically might not be a moralizer, doesn't mean the rest of the republican party isn't anymore, and biden was basically the "generic democrat"

then kamala harris lost to donald trump, somehow, because female candidate weakness to scandals again, i guess? honestly, at this point my thesis starts to break down, but given how unpopular trump is right now, he might suffer another mondale-style landslide in 2028

if you want to know why the democratic party leaders are so afraid of progressive candidates, it's because they grew up in an era where progressive candidates almost always spelled doom for the democratic party -- the situation might be changing right now because the tough economic situation and the ability of candidates to appeal more directly to voters via social media increases the average voter's awareness