Six Points

The Six Points
1. Constitution sets the Framework. Structure and function of U.S. federal government is based mostly on majorities to win separate elections for Chief Executive and the Legislature. (President elected by majority, both chambers of Congress to pass a law, Supreme Court decisions, although there are quirks and exceptions - electoral college for presidential election, filibuster in the Senate, and others.).
2. Exactly Two Parties. Due to majority rule in (1), political coalitions of like minded people will tend to coalesce into two major political parties. This can be seen in the stumbling efforts of 3rd and even 4th candidates in presidential elections and the minor, even temporary role of 3rd and 4th parties. As often noted in political commentary, the non-parliamentary structure of democracy in the U.S. makes a 3rd party a spoiler for its closest minded opponent in any election.
3. Inevitable Polarization. The mixing of conservatives and liberals within each of the two major political parties up until the 1960s and 1970s was mostly a historical artifact dating from the post-Civil War era. While Richard Nixon's Southern Strategy and the efforts of conservative strategists on a national scale ever since are often credited with bringing conservative Democrats into voting for Republicans in the 1970s, 1980s and ultimately switching parties, it should be clear from the pure physics of the exercise of power, that this result, polarized parties, would have eventually prevailed.
4. Inevitable Progress. In any modern post-industrial technologically advanced society, forward progress in the society will generally be associated with greater respect and better treatment for those who have been historically disadvantaged.  In our society, this has meant a positive evolution in the expansion of rights and status of formerly oppressed minorities and women, including LGBT minorities. The simplest way for the improvements in social well-being to occur is through an expanded social safety net and greater role of government.This is the physics of societal progress. Depending upon the actual workings of the apparatus of government, this progress tends to occur in surges (Brown v. Board of Education, Voting Rights Act, Civil Rights Act, Title IX, Roe v. Wade, Affordable Care Act, Windsor decision, among others.)
5. Why Conservatives Fracture. With only two nominal parties for citizens to choose from, each party will be subject to some cleavage into the more extreme and more moderate elements therein. However, the Democratic Party, as the more liberal party, will generally suffer less divisiveness because the tensions will be around incremental change vs. progressive surges, where the key difference is a matter of patience.  Meanwhile, the tensions in the Republican Party, as the more conservative party, will be more starkly between the more moderate, who may be willing to fight to mitigate and shape the changes in society more to their liking by compromise vs. the conservatives among the Republicans, for whom every compromise is either (i) one of a series of small losses or (ii)a strategic loss.
6. Playing to Win. Therefore, the only successful strategy for the more conservative wing of the Republicans is to adopt tactics that fight every progressive step in society that is attempted in legislation, Presidential actions, and court cases. A scorched earth strategy of opposition to the Democrats at every turn combined with efforts to roll back progressive measures in society is THE ONLY WINNING STRATEGY available to the most conservative caucus among the Republican Party. As society has progressed, the tactic of pure obstructionism of legislation is not sufficient for victory. This posture is being supplemented by an aggressive roll-back strategy, which includes multiple court challenges to existing legislation.

If you can accept each of the above arguments as correct or even approximately correct, simple logic leads to a number of useful logical consequences. Actually, only point #6 is needed to understand what is going on, but points #1 through #5 help us understand why this is.

The key conclusions are interesting because (i) it's a matter of tactics, not people, so a lot of observed behavior in American politics can be explained without even discussing the personalities of the players, (ii) there is no need to worry about political bias in drawing reasonable and useful conclusions about the current state of affairs based on the physics of power, and, most of all, (ii) individual behavior of politicians can be explained in terms of a rational strategy, even as brilliant tactics, rather than being considered irrational. The corollaries can help us better understand the failures of the "objective" journalists and craft solutions for our society.

The Key Conclusions
False Equivalence - based on The Six Points, the only conservative Republican strategy for victory is to be strictly obstructionist in order to block legislation that Democrats sponsor or are willing to pass. Therefore, when journalists say "both sides do it" as a knee-jerk reaction to "partisan politics" they are completely ignoring the terms of engagement based on the competitive landscape.
Dysfunction - dysfunction is built into the system. Sooner or later the system starts to break down due to the assymetry of the incentives for conservative Republicans vs. Democrats. Many commentators have described this phenomenon.
Polarization - any discussion of polarization of the parties in Congress or the electorate is not an accurate description unless it considers the different strategic positioning of the Republican and Democratic sides due to the existing structure.
Pressure Points - the rational actors who have an incentive to change their behavior in order to seek better solutions are (1) the moderate Republican members of Congress and (2) objective journalists.
-Moderate Republicans jeopardize maintaining a majority coalition with conservative Republicans capable of governing if they frequently compromise with Democrats. Moderate Republicans could join conservative Republicans in opposing progressive policy, but recognize the importance of compromise as critical to the proper functioning of government and well-being of society.
-Journalistic Fairness - the meaning of journalistic fairness needs to evolve from the definition that worked in the 1960s. At that time, both major parties included conservative and liberal elements in significant numbers which meant that issues were often framed more frequently in factual terms. Geroge Lakoff has written extensively on the very different ways that conservatives and liberals think and reach conclusions about political issues. Conservative Republicans who employ scorched earth tactics driven by stiff opposition to a progressive society have an incentive to avoid discussion of policy issues, such as the likely outcomes if proposed legislation passes. Instead, the winning strategy requires appeals to emotion and avoiding discussion of facts in support of obstructionist tactics. Journalists who observe this behavior need to move away from the "he-said/she-said" so-called balanced approach to coverage of politics and recognize and call out pure tactics when they see them. The "he-said/she-said" approach easily leads to diversion from the relevant policy points.

Beyond the Pale
The strategy of employing pure adversarial tactics in order to win on policy results in actions that are so extreme as to go "beyond the pale". Unfortunately, these tactics are made subject to the "he-said/she-said" journalistic approach even by the objective press , which can make them especially effective.

Things will only get worse
We can see that pure tactics, unencumbered by any sense that some actions may be too extreme in and of themselves, are continuing to be employed with no end in sight.