You really have to love Megan McArdle's economics
The administration line is that they aren't cutting benefits, just payments to providers. I hope that LA Times fact checkers are not so economically naive as to believe that you can simply decide to pay less for something, without any effect on the quantity or quality of what you are purchasing. (If they are, memo to the LA Times: you can apparently cut fact checker Noam N. Levey's salary by 2/3, and he'll still keep working for you).
If you are tempted to believe this, here are some actual facts: Medicaid reimbursements are substantially lower than Medicare's in most cases, and Medicaid patients have a hard time--a very hard time, in many states--finding doctors who will treat them. The opinion of virtually every health care economist I have ever met is that those two things are causally related. . . .Now I have said the same thing several times, but I have to confess that McArdle says it so much better than I did.