Go back to 1964, when the former party of the KKK passed the Civil Rights Act. Then there was Nixon's Southern Strategy and Reagan's dog whistles, followed by Gingrich's "let's win Congress by breaking it" strategy.

All through that, the right and the GOP were getting whiter and more religious, which meant by just math that the left and the Democrats were getting more diverse.

If you want to track it to the point it was obvious and inescapable, go back to Gingrich in the early 1990s. That was when the GOP sort of officially took off the gloves and codified their scorched earth policy. What we see now with Trump etc. is just the logical extension of that.

America has been trending less white and less religious for decades while the Republican Party has been trending more white and more Christian. So of course the left has been getting less white and less religious. With the increasing diversity comes more voices demanding a seat at the table. The power structure of the Democrats is still mostly white, but since something like 90% of African-Americans are Democrats, that means they carry a lot of weight. Given how openly hostile the right is to the LGBTQ community, it’s no surprise gay rights are strong on the left. Given the open and increasing Christian theocracy that drives the right, there’s very little room over there for non-Christians.

In other words, any candidate or policy proposal coming from the Dems is already a compromise, with a din of competing voices at all times. They’ve never been good at messaging.

Meanwhile, over on the right they’ve become largely policy free. They decided several decades ago that the way a white Christian party survives in the face of changing demographics is to prioritize social and wedge issues over policy.

You may disagree, but make a list of what is motivating the two sides of the political spectrum. The right is about anti-abortion, anti-gay rights, anti-CRT… It’s Buckley’s “A conservative is someone who stands athwart history, yelling Stop.” The world is changing faster every year, so it makes sense conservatives would specialize in oppositional social and wedge issues, and those are very simple and easy to rally around.

Meanwhile, over on the left it’s fighting income inequality, pushing for racial/gender equality, healthcare, infrastructure, combatting global warming… You may not approve of how they’re approaching it, but those are actually serious and weighty issues. And very complicated and difficult to solve. And hell to message.

So to address your point, no it’s not new. I’m 58, so I’ve been paying attention to politics for about 40 years, and this has been they way it has been all that time.