Final answer:
The NRA submitted its brief to the Supreme Court in the case of Citizens United v. FEC, where the court ruled in favor of allowing unlimited independent political expenditures by corporations and unions.
Step-by-step explanation:
The National Rifle Association (NRA) submitted its brief in support of super PACs to the judicial branch of the federal government, specifically the United States Supreme Court, in the landmark case Citizens United v. Federal Election Commission. This case addressed the constitutionality of the Bipartisan Campaign Reform Act's (BCRA) limitations on corporate and union political expenditures during election cycles. The Supreme Court's decision in Citizens United v. FEC ultimately held that these limits violated the First Amendment, ensuring that corporations and labor unions could spend unlimited sums in support of or opposition to candidates, so long as the spending was independent of the candidates' campaigns. This ruling profoundly affected the landscape of political campaign financing and was seen as a victory by the NRA and other proponents of free speech in campaign financing.