American has so far had six party systems since the countries inception. Each party inception saw the policies of the parties change, their voters change, and the balance of power change.
The sixth party system started around the civil rights act of 1964 and IMO ended around the time that Obama and Trump were president.
The biggest difference between the 5th and 6th party system is what happened with southern whites. Under the 5th party system (the new deal coalition) southern whites were overwhelmingly democratic. Under the 6th party system after civil rights, southern whites became overwhelmingly republican.
Now we seem to be in a 7th party system. I think the following changes will happen, or have already happened. If other people have ideas I’d like to hear them about what people think will happen under a 7th party system.
Authoritarianism and open bigotry will become much more acceptable to the republicans.
Being progressive will become much more acceptable to democrats.
High school educated whites and people who score high on authoritarianism or bigotry will flock to the GOP.
College educated whites and women will leave the GOP and move more to the democrats. People low on authoritarianism and bigotry will move towards the democrats. College educated whites were slightly republican under the 6th party system, but seem to be slightly democratic under the 7th party system.
I am not sure what will happen to minorities. Generally the democrats had a pretty strong lock on the minority vote in the 6th party system, but I’m not sure if the GOP will make inroads on minority votes in the 7th party system. Especially inroads among socially conservative minority men.
The gender gap will continue to grow. Women were more republican under the 6th party system, while they are much more democratic under the 7th party system. I’m not sure if the gender gap is solely due to women becoming more democratic, or if men are also moving more towards the republican party as well. The gender gap narrowed a bit in 2020 vs 2016, but I think with the overturning of Roe combined with the GOP starting to declare war on divorce and contraception, the gender gap will widen with women moving more towards the democrats.
As far as how it’ll affect geography I see the following changes.
The midwest will move to the GOP. This can already be seen in what happened in the 2016 election. Midwest states that were considered reliably blue in the 6th party system became swing states under the 7th party system. States like MN, WI, MI and PA were reliably blue 20 years ago but are swing states now. States that were swing states under the 6th party system are now reliably red states under the 7th party system. States like IA, MO and OH which used to be more swing states 20-30 years ago are now reliably red.
The south will be less reliably red. Democrats are making inroads in southern states with large urban populations like VA, NC, TX, GA. But FL went from being a swing state in the 6th party system to being more red in the 7th party system.
Democrats will make inroads in southwestern states like NM, CO, AZ, NV.
Democrats will turn the west coast from slightly blue to deep blue in states like CA, OR and WA.
The GOP will make minor inroads in the northeast, but the northeast will still be reliably blue. Trump did better in some NE states like ME, NY, VT, etc vs Romney but those states are still blue. Basically, the NE will go from deep blue to maybe light blue under the 7th party system.
The plains states will remain the same. They’ll still be red.
Under the 5th party system, the democrats held a majority rule on power. In 1964 when LBJ passed the civil rights act, Democrats controlled 66/100 senate seats and 258/435 house seats, giving the democrats supermajorities. In the 6th party system after the civil rights act, power was split about 50/50 between democrats and republicans. I’m assuming the power split will continue to be about 50/50 under a 7th party system.
Also what will happen with libertarians under a 7th party system? Will they stay aligned with the GOP like they were in the 6th party system, or will the authoritarianism and social conservatism of the GOP on the 7th party system drive them out of the GOP?