Country is split 50/50 on politics, and has devolved into basically two camps, both with the mentality of “if you aren’t with us, you’re against us”. This leads to people digging in their heels to stand their ground, right, wrong or indifferent, not based on their actual belief on the issue at hand, but based on how the issue has been tooled to meet the needs of their party.
Talk to a Biden supporter about Trump, they’ll be all “f*ck Trump”. Talk to a Trump supporter about Biden, same deal. That right there is the crux of the issue, you have people so afraid of the other party and being labelled a dem or republican because of what other people might think about them. Same tactic that has been used for centuries to turn one group of people against the other is just being employed by both poltical parties.
You can see it in the blatant hypocrisy that is rampant, which there are so many examples of, to list them would make me vomit.
Edit to add: I wholeheartedly believe only way it will get fixed is a 3rd political party entering the fight. Would take a very strong leader, and significant republicans and democrats BOTH breaking off and saying enough is enough. A party where responsible gun ownership doesn't make you hate guns, wanting a secure border doesn't make you a racist, clean domestic energy (not from the middle east) doesn't make you tree hugging nerd, etc.