Under long-standing First Amendment jurisprudence, the state must demonstrate an important interest before infringing on First Amendment rights. Even after demonstrating such an interest, it must then address it with a “narrowly tailored” solution that goes no further than necessary. Here, neither requirement is met.
The real reason for the aggregate limit is probably pretty simple: it helps the incumbents who wrote the law.
Consider that as of September 25, 2013, the Cook Political Report rated 84 House and Senate races as competitive. This means a citizen, who, for example, wants to help every Republican or Democrat in a competitive race with a maximum contribution, cannot. That contributor would only be able to support nine candidates to the legal maximum, or barely 10% of the competitive races, if he or she donates in both the primary and general election campaigns. As such, challengers feel the pinch of the aggregate cap more than incumbents. Another major source of challenger funding are the party committees, and as already noted, the aggregate caps hurt the parties.
When it comes to the aggregate contribution caps at issue in McCutcheon, Congress created no record of corruption or any other public harm that would be prevented by the caps. The record does not tell us why Congress drafted the provision, what evils it was meant to address, or whether any less speech restrictive approaches were considered.
If members of Congress do raise millions of dollars for such joint fundraising committees, this would help challengers and help the parties. However, if at some point it becomes clear that the lack of a biennial limit creates corruption, there are other more narrowly tailored solutions than the aggregate caps. Most obviously, individuals could still be permitted to support as many candidates as they want, but limits could be placed on solicitations by members of Congress and the president. Other alternatives might consist of stiffer penalties for corruption or more disclosures by elected officials. But the government may not jump immediately to the excessive infringements of a complete ban on further contributions.