The Morris et al. v. Gressette, President Pro Tem, South Carolina Senate, et al., 1976 case involved a challenge to the constitutionality of Section 5 of the Voting Rights Act of 1965 by several South Carolina legislators and voters. The plaintiffs argued that this section violated principles of federalism and separation of powers as it required certain jurisdictions with histories of racial discrimination in voting to obtain preclearance from either the Attorney General or a three-judge panel in D.C before implementing any changes related to voting procedures or practices. However, the Supreme Court unanimously upheld Section 5's constitutionality stating that Congress had broad enforcement power under the Fifteenth Amendment which prohibits racial discrimination in voting rights. The court also noted that there was ample evidence showing persistent discriminatory tactics used against African American voters justifying such an extraordinary measure like preclearance requirements.

In the dissenting opinion for Morris et al. v. Gressette, President Pro Tem, South Carolina Senate, et al., Justice Brennan disagreed with the majority's decision to dismiss the case on grounds of legislative immunity. He argued that this doctrine should not be extended to protect legislators from federal inquiries into potential violations of constitutional rights under Section 5 of the Voting Rights Act. Brennan contended that such an extension would undermine Congress' power and intent in enforcing voting rights protections against racial discrimination through legislation like Section 5. Furthermore, he believed it was inappropriate for courts to create a new privilege shielding state legislators from federal scrutiny when they are suspected of violating federally protected civil rights.