I'm not a political scientist, and I won't even pretend to be. What I can speak to is a nagging perception I've had for a while now. Somehow the Republican Party has appeared to me to have changed quite drastically since the start of the 21st century. I am probably not alone in that assessment. If nothing else, I can't help but notice a sharp change in the party's rhetoric and voting behavior over the past two decades. An anecdote that sticks out in particular surrounds the party's effort to repeal the Affordable Care Act (often referred to as Obamacare) in 2017. I recall at the time that as the Senate leaders were drafting legislation, even party members of the relevant committee responsible for drafting and voting on it complained of being left out of the process. There is a certain chain of command in both major US parties, but it seems as if the chain of command is more rigid within the Republican Party. It also seems as if the party's zeitgeist has shifted to more of an "us versus them" approach to governance, rather than working with and compromising with the opposing party members.
So, that's been my perception, and one that I have probably voiced in personal conversation for a while. Now we actually have some hard data to examine. The Guardian broke a story about a study conducted by V-Dem Institute of Gothenburg, Sweden shows that the US Republican Party has dramatically shifted from being a fairly center-right party similar to many other European center-right parties to that of more autocratic parties such as Hungary's Fidesz. That shift has been most dramatic during the current Trump era. The US Democratic Party, by contrast, has barely shifted on most dimensions in the past 20 years. Encouraging violence, which was unheard of in the Republican Party is now quite noticeable, as has disrespect for opponents. On dimension of disrespect, neither party had particularly glowing reputations, but while the Democratic Party never budged, the Republican Party has come to more openly embrace that particular tactic.Neither party had a glowing record on immigration in 2000, but again, the Republican Party has become openly anti-immigrant whereas the Democratic Party of today is no different than it was 20 years ago. Both parties have shown some shift toward being more populist and anti-elitist (however that is operationally defined). That shift is fairly minor for the Democratic Party (no doubt fueled by an emerging progressive wing led by Bernie Sanders and Alexandria Ocasio-Cortez) but very pronounced within the Republican Party. The Democratic Party has not budged on pluralism and liberalism, whereas the Republican Party is clearly anti-pluralist and its positions do increasingly appear to fit the definition of illiberalism. On matters such as LGBT equality, the Republican Party has remained strikingly consistent in its opposition over the course of this century. The Democratic Party as we know has come to embrace equality. Both parties have moved in opposite directions in terms of espousing cultural superiority, which I am guessing means that of those of European ancestry. The Republican Party is considerably more prone to invoke religion, whereas the Democratic Party of today is no different than at the start of the century. Given that fewer Americans identify with any particular religion, and the percentage of agnostics and atheists has increased, that has been an interesting tack for the Republican Party to take. It's pretty interesting to view the summary. There's plenty of information to digest. But the bottom line is that the Republican Party is indeed apparently considerably more authoritarian than it once was even a mere 20 years ago.
The data and summary can be accessed at the V-Dem Institute's website. If nothing else, the summary itself is pretty concise. Thankfully the data are public, and I am sure that others will examine it and scrutinize the findings. If nothing else, it gives the public an idea of what has happened in our particular political system, and may offer something of a snapshot of the ability of our particular system to function.