The major parties exist purely to gain political power
One flaw in the editorial is it takes the failures and betrayals of Mitch McConnell and blames the Republican Party for them. In a nation of over 300 million people, you can't take one of the two major parties, that consistently get 98% of the vote between them, and boil them down to the leadership of the U.S. Senate. Both parties are way too big and diverse for that and there are far too many factions in each party to make that kind of generalization.
Even in Monroe County, we have our various factions, including party loyalists, business Republicans, libertarians, Christian conservatives, moderates and liberals. When you take that reality and expand it into a national party, it is impossible to make a sweeping generalization about either political party.
But yes - the Republican Party has, far too often, been a corporatist party. But the Democratic Party is also a corporatist party. But why do they exist? What is the ultimate purpose and end goal of the two major parties? To gain political power to use to their advantage. That is the entire purpose of both major political parties, nationally. It's a means to gain power for one clique or another. If the Libertarians or Greens ever became a major party, they would eventually exist to self-perpetuate and gain power as well. Such is human nature.
There are plenty of principled conservatives in the Republican Party, and plenty of principled Leftists in the Democratic Party. There are various principled factions in both parties working to advance their ideological and philosophical interests. The challenge the activist base of both parties face is moving the national leadership to represent their interests - which is not all that easy to do when there are competing interests.
So the key is exercising discernment and choosing the best, most qualified and most principled candidate in a primary election. Does X kowtow too much to the party leadership and is X not aggressive enough in pushing the issues important to voters? Is X consistently failing to act on principle? Primary him and get him out. The important thing (for Republicans) is electing specific principled conservatives to push Reagan's three legged stool of conservatism - economic conservatism, a strong national defense and social conservatism.