What exactly do you mean that 38 states can throw out Congress, President, and Supreme Court? I know that 3/4 of the states, or 38 states, can ratify constitutional amendments, or call a constitutional convention. Is that what you have in mind, either amendments limiting their power, or a new constitution?
Absolute power as per the Constitution is held by 3/4 of states.
Everything can be changed if they have agreement, in spite of whatever Congress, POTUS or SCOTUS says.