Ever since George W Bush served as President of the United States (2001-2009), I have been convinced that if Republicans ever took as much power over the federal government as they did in his first term, it would trigger a second American civil war and/or a second American revolution that would bring down the government and finally force some desperately needed reforms to make American a more ethical, just, and free society. Keep in mind that even though Hillary Clinton got over a million votes more than Donald Trump, the latter still got the most votes in the Electoral College, thus gaining the Presidency. Republicans have also kept control of both the Senate and the House of Representatives, just as they had back in 2001, no doubt due to gerrymandering in many states as well as efforts to suppress the minority votes.
In January of next year, Donald Trump becomes the new President of the United States.The Democratic minority in the Senate proceeds to engage in the same sort of obstructionism against the policies of Trump that Republicans did against President Obama, including repeated acts of filibustering that Republicans cannot stop. A frustrated Trump eventually declares martial law over Washington D C and orders the military to arrest most of the Democratic Senators and perhaps the Democratic House members too after they threaten to impeach him. In response, the states of California, Oregon, Washington, Hawaii, and perhaps Nevada decide to secede from the union. They are followed soon afterward by Illinois (Barack Obama’s home state), and most of the New England states (including New York, Trump and Clinton’s home state). New York’s defection is especially shocking to Trump for members of his family still reside there. Using the internet as their communication and organization tool, the leaders of the revolt form a provisional government among themselves, name themselves the Democratic Union of America, and accept Hillary Clinton as their leader.
In a rage, Trump orders the military to put down the revolt, but the generals, already angry at having been ordered to arrest members of Congress, turn against Trump and federal troops instead storm both the White House and the Capitol building, resulting in Trump, Vice-President Mike Pence, most of Trump’s Cabinet, and most of the Republican members of Congress being arrested or killed while the Democratic members of Congress are freed. With the Chairman of the Joint Chiefs of Staff taking over the capital city, a call is made for delegates to be sent from every state in the union to create a better government to replace the broken one. Most states agree and eventually a new U S Constitution is drafted, ratified by most of the states, and the Union is reestablished. But armed revolts break out in most of the states, which the newly formed government has to deal with over several years.
Dale Husband's Intellectual Rants 
Prediction wrong already. Trump is blaming the Freedom Caucus rather than Democrats for the failure of his agenda in Congress.
Your scenario resembles the Spanish Civil War, but with the ideological sides flipped with right wing Republicans and left wing Natuonalists in your scenario when Spain it was the other way around.
In the vast majority of countries without mandatory voting, it’s hard to tell how much of the people who don’t vote, can’t vote or actually choose not to vote, unless you look at surveys on the topic. I did look at several of them recently. Lots of people in surveys of who didn’t vote and why say that they actually choose not to vote rather than saying they wanted to vote, but couldn’t. Even back in the Spanish election of 1936, which was a really important election in retrospect, there was still a sizable amount of people too apathetic to vote.
The weirdest part of our elections isn’t the districts or the electoral college, but the first past the post voting system. Countries like France have runoff elections for whenever candidates for a race fail to reach 50%+1 in any race. America having a de facto two party system doesn’t guarantee candidates reaching 50%+1 nationwide, statewide, districtwide, or at any level. Americans don’t really understand the fact that a candidate being able to win with at least 35% or somewhere near there without having to go to a runoff election is weird to people in other countries. Interestingly enough, more people vote during second rounds than first rounds in France. Even though Americans tend to ignore the existence of third parties, they do exist and do get enough votes to be notable.
https://en.wikipedia.org/wiki/Template:US_Third_Party_Election
The above template shows various gubernatorial, senatorial, representative, and presidential election with size able third party performances.
Third party candidates for Congress who got 5% or more of the vote
2006 37
2008 59
2010 66
2012 54
2014 66
2016 70
Note: the number of districts may be smaller in the case there were multiple third party candidate getting 5% or more in a certain year in the same district.
Senate stats
1964 1
1966 3
1968 4
1970 4
1972 1
1974 4
1976 2
1978 4
1980 1
1982 1
1984 1
1990 1
1992 5
1994 5
1996 2
2000 5
2002 8
2004 1
2006 4
2008 4
2010 5
2012 6
2016 6
Note: number of states may be smaller in the case that multiple third party candidates each got 5% or more in th same state in the same year.
https://en.wikipedia.org/wiki/List_of_third_party_performances_in_United_States_elections
You can look of the races themselves as well as the vote percentages of all the candidates on the links to the specific elections in the article above. The template only links some of the elections that qualify, but the article goes in depth into each election where at least 5% voted third party. Regardless of saying hypothetically who third party voters would have voted for, it still does have a plurality without a majority candidate winning.
CGP Grey is one of my favorite YouTube channels. He has done several videos on why FPTP voting is the worst voting system ever.
The video is on why the most recent British general election was the worst in history. Basically, the voting system is the extremely near sighted focus on each individual district or riding. If a party (or independent) gets more votes than any other in a district or riding, they get one seats. All others get nothing. This is only noticably problematic, once you zoom out of the inidivudal district to the nation as a whole. It’s also problematic in the inidivudal district, since a party can get less than one out of four votes, and it would still be a plurality as the example from a district in Ulster shows.
Back to nationwide, a party can get a whole lot of votes nationwide, but as long as they get second place or lower in each district or riding, those votes don’t get any representation. This leads to the disconnect between percentage of votes and percentage of representation between various parties. While I don’t know if Britian has issues with gerrymandering and voter suppression, but they share the same voting system with America, as well as other parts of the former British Empire.
Dale, you never specified if your state/district is red or blue. It would be helpful to look up party strength there. Also, in the previous post, I linked strong third party showings, so I was curious if there were any of those in your state/district in the recent four to five decades?
Speaking of third parties again, I should note 2016 was the election where more people voted third party than any election in recent history except 1996 and election where even more people did that aren’t that recent. America is strange as part of the former British Empire. It is a presidential republic, unlike the constitutional monarchies of the Commonwealth Realm or the parliamentary republics of the rest of the Commonwealth of Nations. This brings up the issue of should a President be elected by a plurality of the popular vote instead of 50%+1 of the Elecotral College? Other countries don’t have Electoral
Colleges for President, but they also don’t have the plurality winner of the first round win automatically, despite not getting a majority of the popular vote. If 5%, 15%, or even 25% vote third party, it means whoever got the most popular votes, didn’t actually win the popular vote. A change to a popular vote for the Presidency, would need either a runoff or exhaustive ballot, eliminating each candidate that doesn’t get a certain minimum percentage and then eliminating each last place vote getter until someone gets 50%+1 one of the popular vote. (Yes, a third party candidate did get more than 25% back in 1912.)
I live in Texas, which has been hard-core red since the late 1980s. It, like the rest of the south, has also been overwhelmingly conservative for even longer.