I'd say its much more entrenched now.
Donald Trump, as a politician/President was still very much an unknown in 2016. I think that gave people a little wiggle room - "I kind of like what an outsider might do in Washington, even if I don't know what that looks like."
Now, virtually everyone knows what a Trump presidency looks like, and most people will have a general idea of what a Biden presidency will look like. People who like what Trump as done, will vote Trump, people who don't like what Trump has done will probably vote for Biden. But very few people don't know where they stand on that issue.