It would be a spectacular ending to the American Experiment
An excerpt from Wikipedia, circa 2150, on the United States of America
...but Reaganomics only provided the stage for the last days of the USA. Despite the election and re-election of President Obama in 2008 and 2012, respectively, the age of Biden caused him to not seek advancement to higher office after two terms as vice-president. Facing a wide-open field in 2016, the marginalized, radicalized, nearly-extinct Republican party squared off with a Democratic party a victim of it's own sucess. The Democrats were unable to unite behind two popular choices, populist Dennis Kucinich and moderate Wesley Clark. The selection of Robert Kennedy, Jr. as Clark's running mate was seen as an appeal to more radical liberals, while Kucinich's VP candidate, Bill Richards, was seen in a similar fashion to moderate progressives.
After an extremely contentions primary season, the deadlock was finally broken with a roll-call vote at the Democratic convention in August of 2016. With the superdelegates finally picking Clark/Kennedy for 2016, an angry Kucinich quickly joined the Green Party and continued running for President.
With voter turnout at an all-time low as sustained economic stresses discouraged citizen activism and participation, Paul/Bachmann won by a bare 3 electoral votes and only 43% of the popular vote, due to the siphoning-off of votes to the Green Party by Kucinish. The Green Party was now a major factor in the domestic political scene, having won 4 congressional seats, but the fate of America was to collapse before they could advance any further.
Under Paul/Bachmann, Reaganomics went into overdrive. The balanced federal budget once again fell into deficit as taxes were slashed, while the minimum wage and the 40-hour work were were no longer required by law. Although President Paul did pull the US out of NAFTA, he was unable to get the Senate to repeal GATT. And with the collapse of the health-care industry in 2018 (35% of the economy), the default on Treasury securities in 2018 and 2019, and the collapse of the financial sector in 2020 (50% of the economy), the central government collapsed.
Abandoned, the various states were forced to form their own nations. Civil strife spread across the former USA as regional, ethnic, and racial forces fought over the boundries and resources of these new emerging countries. The California Confederacy was the first to emerge as a nation, compromising the bottom two-thirds of what had been the State of California. Other states soon followed, with part of Florida becoming the newest Caribbean nation. Long-dormant Southern nationalist feelings resulted in the rise of the Deep South as the Confederate States of America, while Texas was torn in civil war between the ethnically Mexican counties that wanted to form a state and join Mexico and ethnically Caucasion counties that desired to re-join the CSA.
Border skirmishes broke out in the crowned Northeastern states as urban counties, facing a collapse of the food distribution network, had their populations scramble outworks to rural areas in search of sustinense. Hastily-organized militias barricaded various parts of Interstate 95 as Connecticut and New Jersey attempted to keep New Yorkers from desending upon their agricultural land. Chaos reigned.
Finally, after a year of such fighting, China invaded with the stated purpose of securing the US stockpire of nuclear weapons.