ACA benefits specifically are not available to undocumented immigrants. However a small amount of provision is given to Hospital ER services for uninsured. this is how I had some of my ER costs earlier this year paid. ERs are obligated to treat everyone so the undocumented can receive ER care if they risk it.
This is the small truth made into a 'abuse', 'threat', 'war', ... from human non-citizens. The amount is miniscule compared to the benefits citizens can get.

I have been paying out of pocket since my ER visit. Thankfully no hospital stays etc. and finally I am just getting stabilized financially enough recently and the costs may be out of reach again because of this current BS.

Meanwhile I fight to ensure my son doesn't get care services stripped because of budget reductions. this year there is a transition in classifications, categories and criteria for services as his yearly assessment is happening now too. And there is complications in regard to the company to provide oversight because the current one in place is no longer part of the recognized entities and simultaneously the case manager to oversee that is in a transition which is usually 6-12 month occurrence as well.

It's a f'n madhouse right now.