....after December, tens of millions of Americans who can't afford health insurance won't have any coverage at all.

Those are set to expire at the end of this year, but that would not affect any of the things you listed (for people who can still afford insurance).

..I think some or all of those have some protections still active under the ACA.

Baked into the “One Big Beautiful Bill” / reconciliation package:
-Pre-enrollment verification & stronger documentation checks
The law would require more stringent verification (income, immigration status, coverage history, residence, family size, etc.) before someone can receive premium tax credits or cost-sharing reductions.
This also effectively ends auto-renewals of subsidized plans (or at least makes auto-renewal with credits harder).

-Loss of eligibility for certain immigrants / removal of DACA eligibility
The law rescinds eligibility for marketplace subsidies/coverage for certain lawful immigrants, including DACA recipients.
Hundreds of thousands of people who currently use ACA marketplace plans might lose eligibility entirely (not just lose subsidy).

Expected consequences:
-Overall rate increases. Insurers are already filing rate increases in anticipation of this, in part because they expect healthier enrollees to drop out, worsening the risk pool

-States running their own marketplaces must implement new verification, enrollment, and eligibility rules, i.e., upgrading state IT systems.

...during the pandemic.

The enhanced premium tax credits, part of the American Rescue Plan Act and extended through the Inflation Reduction Act, led to record enrollment in the ACA marketplace, with millions of people gaining access to health insurance coverage.

The credits also eliminated the "subsidy cliff," which previously prevented individuals with higher incomes from receiving financial assistance for health insurance.

Take it from there... what were the politics at the time, Senate balance, etc.

...it was passed in a pandemic rescue plan, and if we're honest, was a bit subversive in how it not only extended coverage to millions, but allowed higher income folks to benefit from it.

Can you really imagine republicans agreeing to a permanent one then? Go back and look at the political balance of power for yourself and make your own judgment

Maga's really steamed we put this over on them, did it FOR ALL Americans, and they'd like nothing more than to return us back to a time where these millions were shit out of luck.

Most people get their insurance through their employer, or programs like Medicare and Sups, Medicaid, VA, etc - like over 220 million

Not saying the 22 million needing the credits aren't important, but I get why they question it as a primary demand

...about 50% offer it.

Back to the bad old days when you prayed that you had a state that required anyone with more than 10 employees was required to pay worker's comp insurance and you only got sick or injured at work, because the only heath care insurance that was "affordable" gave your family 1 each free GP visit a year, 20% off 4 visits a year per insuree for specialists, and 50% off coupons for pharmacy, lab work and other specific diagnostic tests at designated locations. No deductible.

I worked shipyards for a small company that had that insurance for 3 years, 1992 through 1996. Along with crappy dentist and vision.

I'm still carrying body trauma and damage from that period.

But one thing I can say - if that's the return to the type of insurance the GQP wants for poor and low pay working people, they can also proudly point out they're fixing the Social Security issue, by increasing the amount of people who won't last much past retirement...just like US in the 50's and 60's.

This is about leopards and 'have the day you voted for' as much as it is about any specific policy defense.
Those 22 million people are gonna decide real quick that it isn't worth having their monthly premiums double just because Donald Trump doesn't want anyone to know he put his dick in a child.