I am walking through this for my own education because it seems like Johnson is trying to confuse multiple items.
Johnson is specifically citing Emergency Medicaid use, which does not require legal citizenship paperwork, as a drain on resources. That use by undocumented immigrants represents less than 1% of Medicaid funds seemingly an indication it is not much of an impact. There have been no changes here, as federal law requires hospitals to treat emergency seeking patients. So, no real point of discussion when it comes to current negotiations.
The other issue Johnson leaps into is the narrowing of eligibility for full Medicaid coverage for documented immigrants. The recent Republican bill narrowed eligibility essentially removing the more vulnerable immigrants like refugees, trafficking victims, etc. In reality, a heartless move but seemingly not a big financial impact from my point of view. Democrats do want to repeat this rollback but also not a large part of their negotiation, as their main focus are the credits which the caller does well to highlight.
All this fair?