upheld the Foreign Agents Registration Act of 1938, under which several Canadian films were defined as "political propaganda", requiring their sponsors to be identified. Campaign finance In Buckley v. Valeo (1976), the Supreme Court reviewed the Federal Election Campaign Act of 1971 and related laws, which restricted the monetary contributions that may be made to political campaigns and expenditure by candidates. The Court affirmed the constitutionality of limits on campaign contributions, saying they "serve[d] the basic governmental interest in safeguarding the integrity of the electoral process without directly impinging upon the rights of individual citizens and candidates to engage in political debate and discussion." However, the Court overturned the spending limits, which it found imposed "substantial restraints on the quantity of political speech". The court again scrutinized campaign finance regulation in McConnell v. Federal Election Commission (2003). The case centered on the Bipartisan Campaign Reform Act of 2002 (BCRA), a federal law that imposed new restrictions on campaign financing. The Supreme Court upheld provisions which barred the raising of soft money by national parties and the use of soft money by private organizations to fund certain advertisements related to elections. However, the Court struck down the "choice of expenditure" rule, which required that parties could either make coordinated expenditures for all its candidates, or permit candidates to spend independently, but not both, which the Court agreed "placed an unconstitutional burden on the parties' right to make unlimited independent expenditures". The Court also ruled that the provision preventing minors from making political contributions was unconstitutional, relying on Tinker v. Des Moines Independent Community School District. In Federal Election Commission v. Wisconsin Right to Life, Inc. (2007), the Court sustained an "as applied" challenge to BCRA, holding that issue ads may not be banned from the months preceding a primary or general election. In Davis v. Federal Election Commission (2008), the Supreme Court declared the "Millionaire's Amendment" provisions of the BCRA to be unconstitutional. The Court held that easing BCRA restrictions for an opponent of a self-financing candidate spending at least $350,000 of his or her own money violated the freedom of speech of the self-financing candidate. In Citizens United v. Federal Election Commission (2010), the Court ruled that the BCRA's federal restrictions on electoral advocacy by corporations or unions were unconstitutional for violating the Free Speech Clause of the First Amendment. The Court overruled Austin v. Michigan Chamber of Commerce (1990),