Which political case was pivotal in shaping modern campaign finance laws in the United States?

The significance of Citizens United v. FEC lies in its profound impact on campaign finance in the United States. This 2010 Supreme Court ruling held that corporations and unions have the same political speech rights as individuals under the First Amendment. Consequently, it allowed unlimited independent expenditures for political campaigns by these entities, fundamentally altering the landscape of campaign financing.

Prior to this decision, federal laws restricted corporate and union spending on political advertising in the lead-up to elections. Citizens United challenged these laws, arguing that such restrictions violated free speech. The Court's ruling not only removed many of the limitations that previously existed but also led to the rise of Super PACs—political action committees that can raise and spend unlimited amounts of money to advocate for candidates, as long as they do not coordinate directly with their campaigns.

This case triggered a significant increase in the flow of money into elections, leading to ongoing debates about the influence of big money in politics and questions about the integrity of the electoral process. As a result, Citizens United v. FEC is pivotal not just as a legal precedent but as a catalyst for major changes in how campaigns are financed in the U.S. electoral system.