Cases like nfib v. sebelius and shelby county v. holder illustrate what trend that has appeared in supreme court decisions since the 1990s regarding the relationship between states and the national government?

Explanation:

In NFIB v. Sebelius law suit, National Federation of Independent Business filed a suit against ACA claiming that it was unconstitutional because of  mandate which forced the citizens to purchase health insurance.

In Shelby County v. Holder case, Shelby County filed a case against the Congress that section 4(b) and section 5 are unconstitutional which is relevant to the issue of voting rights.

answer; criterion validity

answer; /// charles darwin;