So this is a hypothesis I've been batting around. Not fully developed, so I'm sharing as a tweetstorm. Feedback welcome.

To truly understand American politics in the age of Trump, you need to understand liberalism (but not as Americans use the term). 1/

1a/ (Note that I'll be making some oversimplifications in this thread due to medium and desire to present a coherent hypothesis. I'm looking for engagement with ideas primarily, not nitpicking, though nitpick away if you want.)

2/ In the U.S., "liberal" is used as a synonym for "progressive" or "left-leaning," but we're idiosyncratic that way. Most of the rest of the world uses "liberal" to refer to ideas coming out of "classical liberalism" — Locke, J.S. Mill, etc.

3/ *Precisely* defining a term like "liberalism" is hard, but the favorite definition I've seen is that it's an ideology that is concerned with "protecting the liberty of individuals." Both parts of that are important.

4/ Liberalism is obviously concerned with liberty — it's right in the name. But just as importantly, liberalism is an ideology whose primary unit of analysis is the *individual* — not socioeconomic classes, or racial/ethnic groups, or religious communities, or families, etc.

5/ Beyond that general focus, though, there's huge variation among "liberals." For example, some define "freedom" narrowly — "negative liberty," the right to not have the government tell you what to do.

6/ Other liberals prefer broader definitions of "positive liberty," where, say, being poor infringes on your liberty, by constricting your options. Liberals fight about which is better, but both are varieties of liberalism.

7/ Similarly, liberals disagree about the greatest threat to individual liberty. Some see the national government as the biggest threat & bolster local gov't, private associations, business, churches, etc. as a bulwark.

8/ Others see the biggest danger to individuals' liberty as precisely being those local governments, private associations, etc., and want to use the federal government to protect people from these "intermediary institutions."

9/ The point is, "liberalism," understood along these lines, is not definitionally an ideology of the left, or of the right. There are left-liberals and right-liberals.

10/ There are also plenty of political ideologies aside from liberalism. Marxism, for example, sees social class rather than individuals as the primary unit of analysis. Nazis thought in terms of a racial "nation." Both are more concerned with "power" than "liberty."

11/ All that is prologue to say that historically, American politics has been dominated by liberals. The Republican Party was principally a right-liberal party, while the Democratic Party was a left-liberal party.

12/ There were, of course, non-liberals in both parties – people who shared a lot of policy goals with right-liberals or left-liberals, but for different reasons and through different reasoning. But they were largely marginalized.

13/ In other countries, the political spectrum is wider, with liberals just one smaller groups among socialists, communists, Christian Democrats, ethno-nationalists, and more.

14/ When people criticize Democrats and Republicans for being basically the same, that can seem absurd if you look at the very real policy differences between the parties. But understanding that both come from & are constrained by liberal frameworks makes that make more sense!

15/ But think about American politics since 2015 or so. What are the two most novel phenomenons? Bernie Sanders, a Democratic Socialist, and Donald Trump, who is many things, but is definitely NOT is a liberal.

16/ The fierce rivalry between Bernie Sanders and Elizabeth Warren, despite very similar policy positions, makes more sense through this lens. Warren is a left-liberal. Sanders comes out of non-liberal strains of the left.

17/ Trump, similarly, tramples disdainfully over liberal political mores. Barack Obama & George W. Bush both always tossed platitudes into their speeches about respecting people of other beliefs & creeds (even if their opponents were skeptical). Trump doesn't.

18/ Congressional Republicans, mostly right-liberals, largely back Donald Trump. But if you look at the areas where they DO criticize him, it's most frequently on areas where Trump violates liberal mores about freedom of speech, conscience, etc.

19/ In a European political system, Marco Rubio and Donald Trump would not be part of the same political party, though they might serve in a coalition government together. The same for Bernie Sanders & Joe Biden. (Of course, this actually describes Sanders & Biden.)

20/ Liberalism in its various forms historically has had its strongest support among the professional class living in and near cities. The Republican Party's collapse in suburbs under Trump is driven precisely by this group.

21/ (The realignment of the suburbs predates Trump, of course, and has lots of causes; this hypothesis is Trump's illiberalism has accelerated the trend.)

22/ Who knows what the future will bring, but the old model of American politics, where the center of gravity was liberal and non-liberals of left and right had to either forge alliances with liberals or be completely marginalized, seems battered at best.

23/ Both the illiberal left and the illiberal right have risen in power in recent years, and become more vocal in their demands. First-past-the-post voting makes a two-party system very durable...

24/ ...but both America's coalition of the left and coalition of the right will have to either find a way to accomodate new illiberal factions, or find ways to defeat or co-opt them, or possibly splinter into separate parties.

25/ Thanks for bearing with me! As I said, this is a hypothesis, with lots of oversimplifications. I welcome questions, comments, historical or philosophical corrections, etc.