lol every election they think they will become more progressive and beat out republicans.
Yet every election, another set of younger people reach adulthood - where they actually have to pay taxes instead of being a net-negative... and they immediately have a more conservative outlook all of a sudden
The funny thing is that US society is becoming increasingly progressive — it's just that Democrats are only kinda-sorta involved. However, this still means conservatives are increasingly marginalized.
For instance, take LGBTQ rights. The US in the '00s was starting to embrace LGBTQ issues in earnest, but this was an era when Bush Jr. could get away with DOMA and even Obama was hesitant to support gay marriage (though this may have been for strategic reasons). Flash forward 10-15 years and most people are comfortable with gay marriage, transgender people are making progress (if slowly) on their rights, and it's no longer a bold move to come out as LGBTQ in most fields. The GOP, however? It begrudgingly accepted some things, but it's still trying to court bigots (see Trump's measures) and otherwise drag its heels. Society has moved on, but the GOP hasn't.
This applies to other fields, too. Renewable energy, EVs and other environmental efforts have much wider acceptance, and they're virtually certain to dominate in the years ahead. The GOP? Still desperately trying to prop up fossil fuels. They know they're fighting a lost cause but don't care, whether it's pure partisanship or just those sweet, sweet industry bribes.
This shift is also true for issues like
public healthcare.
This doesn't mean that the progressive wing of the Democrats will suddenly rise to power and dominate the polls. But it rejects your notion that people become more conservative over time, and suggests that American conservatives will have to face a moment of reckoning at some point — either they drag their ideology into the 21st century or risk being rendered permanently irrelevant.