What was determined in the Supreme Court case Citizens United v. Federal Election Commission?

The Supreme Court case Citizens United v. Federal Election Commission established that corporations and unions have the right to spend unlimited amounts of money on political campaigns as a form of free speech under the First Amendment. The ruling determined that political spending is a protected form of expression, meaning that restrictions on independent expenditures from corporations and unions in elections violate the free speech guarantees.

This decision significantly changed the landscape of political finance by allowing for greater corporate and union involvement in elections, which many argue has led to increased influence of money in politics. This ruling has been a pivotal point of discussion in conversations about campaign finance reform and the role of money in democratic processes.

The other options do not accurately represent the ruling: government regulation of political funding is limited by this decision, individuals are not the sole contributors to campaigns post-ruling, and the case did not address the issue of public funding for campaigns.