In three charts, the author depicts the degrees of polarization in 1994, 2004 and 2017. Between 1994 and 2004 the shifts were relatively small, with both becoming a little more "liberal". However from 2004 to 2017 both move toward their respective extremes, but the trend is much more pronounced on the left.
What explains it? Drum does not offer an explanation, but one can surmise that it may have something to do with the rise of social media during the latter interval. As to electoral consequences, he cites another data analyst ( as self-described socialist) who points to some interesting data from the 2020 presidential election that seems to challenge the presumption that demographic change guarantees Democrat dominance in the long term.
In that election, the Democrats gained slightly among non-college educated whites, but markedly among college educated whites. However there were significant gains for Republicans among working class non-whites, especially Hispanics, their voting patterns moving closer to white conservatives, especially among those with strong concerns about crime and public safety.
I've made this point many times before, and I want to make it again more loudly and more plainly today. It is not conservatives who have turned American politics into a culture war battle. It is liberals. And this shouldn't come as a surprise: Almost by definition, liberals are the ones pushing for change while conservatives are merely responding to whatever liberals do. More specifically, progressives have been bragging publicly about pushing the Democratic Party leftward since at least 2004—and they've succeeded.
Now, I'm personally happy about most of this. But that doesn't blind me to the fact that "personally happy" means nothing in politics. What matters is what the median voter feels, and Democrats have been moving further and further away from the median voter for years.
At the subgroup level, Democrats gained somewhere between half a percent to one percent among non-college whites and roughly 7 percent among white college graduates (which is kind of crazy). Our support among African Americans declined by something like one to 2 percent. And then Hispanic support dropped by 8 to 9 percent....One implication of these shifts is that education polarization went up and racial polarization went down.
....What happened in 2020 is that nonwhite conservatives voted for Republicans at higher rates; they started voting more like white conservatives....Clinton voters with conservative views on crime, policing, and public safety were far more likely to switch to Trump than voters with less conservative views on those issues. And having conservative views on those issues was more predictive of switching from Clinton to Trump than having conservative views on any other issue-set was.
....This lines up pretty well with trends we saw during the campaign. In the summer, following the emergence of “defund the police” as a nationally salient issue, support for Biden among Hispanic voters declined. So I think you can tell this microstory: We raised the salience of an ideologically charged issue that millions of nonwhite voters disagreed with us on. And then, as a result, these conservative Hispanic voters who’d been voting for us despite their ideological inclinations started voting more like conservative whites.