It has been happening since Theodore Roosevelt was president (stopped a little for Harding and Coolidge, but that’s it). This is one thing both parties are equally guilty of. There has also been a major shift of power away from state and local governments and to the Federal government. It has probably been very destabilizing, and to a certain extent explains the current radical polarization. I suspect if you brought some politicians from the 19th century to visit, they would being saying “I told you so”.
A president who rules by decree reduces the utility of any politics other than the election of the president. Switching power to the Federal government means that which group of states has control allows them to go after policies that are absurd to the rest of the country. It means if the Feds oppose gas-powered cars, people in areas where electric cars aren’t practical are angry. Most of the “culture war” issues become “hot” since by definition a federal solution is being imposed on all states whereas in the past states had more options.