Show me where in the Constitution the Federal Government has the right to demand that states cough up voting rolls, and the prescribed penalty should they refuse?
Article IV, Section 4, Clause 1:
“The United States shall guarantee to every State in this Union a Republican Form of Government.”
... which is impossible to do without integrity of elections, as they are essential to having a republican form of government.
The feds have long got around that by simply withholding funds from the states.
Did you read the request?
“If publically available under the laws of the state....”
In other words, if the voter rolls are public records, (as they usually are) they asked for copies.
By definition, public records are PUBLIC and available to anyone, including the federal government. Refusing to provide them is clearly obstruction....and probably because the state officials know their voter rolls are filthy with fraud.