What is the basis for this claim?
> believe that their position is not only correct but above debate and above the political and legal process
You seem to be accusing everyone who disagrees with you of malice and abandonment of all principles - more or less evil. I would counter that this kind of argument is only ever made in bad faith in an attempt to demonize those who don't agree with you.
> politics and law are merely vehicles for imposing the moral views of highly educated professionals on the unwashed masses.
And one could likewise say that much of conservative thought is an attempt to force people to adhere to certain religious values using state coercion. But that would just be an opinion, not a fact.
What is fact is that many (possibly most?) conservative policies and doctrines do not enjoy majority support in the United States, yet are being rammed down our throats regardless because those policies are a) supported by those in power and b) convenient wedge issues or rallying cries for a small minority of the voting base - a minority that happens to be highly motivated.
Even the current composition of the court was a blatant power grab to deny Obama's constitutional right to appoint a justice with a made-up rule that it was "too close" to an election. Then immediately discarding that so-called rule when Trump was in the same position. In that sense the current conservative majority is illegitimate. Regardless of how you think any specific SCOTUS decision should go I hope you'd agree that a court that the majority of Americans believe to be illegitimately stacked is not a good thing for the stability of our separation of powers.
For that matter the overall tilt toward conservatives in House representation thanks to gerrymandering along with over-representation of conservative thought in the Senate due to the 2-senators-per-state rule undermines the legitimacy of Congress and the entire government. You can only get away with preventing the majority from being able to enact any significant policies for so long before a representative government collapses. Granted that might take tens or hundreds of years but in the long term it erodes the very foundation of our society. I find that very concerning personally but some people would rather win at any cost (witness Trump's recent loss and the fact that some conservatives attempted to sacrifice free & fair elections for a single win of a single presidential term. How cheaply they were willing to sell out!)