I think some it is explained by sincere differences in policies.   “Best for the country” is up for true debate.  There are those that truly believe ‘an unregulated militia’ is ‘best for the country’.  Others believe a ban on war-like weapons is ‘best for the country’.    I am not sure those two sides can compromise. 

BUT, I think your question is best answered by political scientist David Mayhew. 

SideNote:  A lot of the early political scientists got the big concepts right explaining 80% – and the rest of us are just proving nuance. 

Mayhew wrote “Members of Congress are single-minded seekers of re-election….” And I think that is the answer to your question.    

Politicians’, parties’, donors’, consultants’, etc. actions are explained by that statement.  I mean it makes sense, one can’t affect policy, if one is not in office. 

And, this explains the often cowardliness of politicians. 

This explains the many, many conversations I have had behind closed doors with elected politicians and party officials that know that much of the current political climate is complete and utter bullshit then opens the door to spout that exact bullshit. 

Why?

Representatives have pretty cool jobs (if you don’t mind the death threats, constant travel, and pesky constituents), and the halls of power are marked with scalps of the Liz Cheneys of the world while Lauren Boebert retains the title of “Representative.”

Leadership, true leadership, is often at first seen as blasphemy – especially in tribal politics.   What often is ‘best for the country’ is telling your friends you disagree.  The price is often being shunned and ostracized – see – Jeb Bush, Liz Cheney or Adam Kitzinger. 

What to do?

So, if one wants to affect the behavior of politicians – one must affect their re-election odds.   

Want them to be more responsive to your opinions?  One must organize in numbers large enough to at least have them fear you at re-election time.  If not, one gets lip service, if not ignored completely.