Governing Is Hard

Comparatively speaking, Republicans have a huge advantage over Democrats when it comes to governing. Even during an extremely dysfunctional time of unified government in 2017 and 2018 the Republicans were able to push their two item agenda forward by getting tax cuts and pushing Judicial appointments at all levels of the Federal bench. Simply put, it's easier to pull everyone together when you have more narrow objectives. Additionally, much of the Republican agenda can be moved via Executive Branch action, such as deregulation efforts. Taken together, they have an easier time governing.

Another factor, however, lies in the party leadership's willingness to approach politics as a zero sum game. Mitch McConnell is the expert in this approach. His philosophy can be clearly seen in his refusal to hold a vote for Merrick Garland's nomination to the Supreme Court in 2016, while pushing through Amy Coney Barrett's nomination in 2020. Garland, nominated on March 16, 2016, was railroaded by McConnell, the Senate Majority Leader at the time, because it was too close to a Presidential election in his opinion (citing Joe Biden's prior statements; the man is skilled at this!). Coney Barrett, nominated on September 26, 2020, was rushed through the process and confirmed to the court in spite of her nomination coming six months later into the process than Garland's. 

McConnell is willing to make up rules and precedents to serve the party's larger goals, and is equally willing to discard those same things if it serves those same goals (or, at least, find new rationales to justify the discarding). McConnell, by the way, knew that the huge tax cuts passed in 2017 couldn't pass the Senate filibuster threshold. So what did he do? He fast tracked it using the budget reconciliation process. There was no hemming or hawing about the need to work across the isle; simply a unilateral pushing of the broader agenda. And, of course, he led the path to eliminate the filibuster for Supreme Court nominees to get Neil Gorsuch on the court quickly for the very seat that Garland was refused even a vote for. 

Of course it was Harry Reid (D) who eliminated the filibuster for lower court nominations in a prior congress. While that move was in response to unprecedented opposition to judicial nominees by then Minority Leader McConnell, the reality is that it was Democrats who broke that seal. The difference is that McConnell not only was glad they did it, but then used it to further push his agenda. Democrats may have gotten some of Obama's nominees through, but McConnell and the GOP then had carte blanche to load the courts aggressively with no real opposition throughout the Trump Administration. They also had precedent that they were able to point to, by the Democrats, for their action to eliminate the filibuster for the Supreme Court. 

If the shoe was on the other foot, there is no doubt what McConnell would do at present with a GOP house and control of the White House: he would push through their highest priority agenda using reconciliation if he could. Beyond that, he would do it with a smile. McConnell is better at politics than his Democratic counter parts. Some of that is due to him heading a coalition that is far more narrow in their agenda (lower taxes, deregulation, anti-abortion, pack the courts, etc.). Part of that is that he recognizes that no matter what you do you will lose power, as that's the nature of the system. Given that, you are incentivized not to work with the other side, but instead to push through as much as you can, as fast as you can, for as long as you can. This definitely isn't right, but when you see the Democrats force through something on budget reconciliation and hear the cries from the other side of the aisle just remember: they would have done the same exact thing.