Is the Supreme Court going to invalidate campaign finance laws further in the aftermath of its 2010 decision in Citizens United?

The court heard arguments Tuesday in the case of McCutcheon v. FEC, in which plaintiffs Shaun McCutcheon and the Republican National Committee are seeking to overturn aggregate limits for political donations in federal elections. Currently, federal law doesn’t just limit the amount of money that any individual can give to any federal candidate or campaign committee but the total amount that can be contributed. Individuals can give no more than $48,600 to all federal candidates and an additional $74,600 to all political party committees. The question is whether the aggregate limits unconstitutionally inhibit the free speech of donors or are a necessary check on corruption, like a restriction on giving “a Maserati to the secretary of defense,” to cite an example used by Solicitor General Donald Verrilli.

A lawyer representing Senate Minority Leader Mitch McConnell (R-KY) in the case joined McCutcheon’s attorney Tuesday to argue against the constitutionality of aggregate limits. McConnell is a longtime opponent of campaign finance laws and in 2003 challenged the constitutionality of the 2002 McCain-Feingold legislation in McConnell v. FEC.

One key argument made by the plaintiff was that current limits on contributions represent an absurd limitation on speech. How is it legitimate, the plaintiff argued, for a donor to make maximum contributions to 17 federal candidates, but the 18th would have a corrupting influence? The plaintiff also noted that the legal environment in 2013 is different from that of 1974, when Congress first passed aggregate limits, and 1976, when the Supreme Court upheld them in Buckley v. Valeo.

If these aggregate limits to individual candidates and party committees are struck down, an individual could donate up to $3.5 million in a single election cycle to candidates. However, in the post-Citizens United landscape, to some that might not seem like a significant sum. “I don’t think $3.5 million is a heck of a lot of money,” said Justice Antonin Scalia.

Verrilli, arguing on behalf of the U.S. government, said aggregate limits have an important role in preventing corruption. After all, that $3.5 million can be rerouted in a number of ways to violate campaign finance laws, he said, including through state parties back to federal candidates. Further, handing over one $3.5 million check, even if the money will be parceled out to a number of candidates, has the potential to lead to corruption by creating an implicit quid pro quo, the solicitor general said. But in what court watchers warned was not a promising sign for the government, Justice Samuel Alito dismissed Verrilli’s arguments as “wild hypotheticals that are not obviously plausible.”

The case was heard on appeal from the United States District Court for the District of Columbia, which ruled unanimously in favor of the Federal Election Commission in September 2012. Court watchers are far more skeptical about this case, though that doesn’t mean the justices will strike down all restrictions on aggregate limits. Chief Justice John Roberts seemed to indicate that while he is skeptical of aggregate limits on donations to individual candidates, he might still be open to maintaining current law as it pertains to party committees. Roberts wondered aloud, “Is there a way to eliminate that aspect [of limits on donations to candidates] while retaining some of the aggregate limits?”

Although the Supreme Court is not expected to issue a ruling on McCutcheon for several months, this is almost the same court that overturned a century of campaign-finance law in Citizens United, and court watchers are expecting at least part of the law to be struck down. But an unexpected outcome is always possible. These are the same court watchers, after all, who ended up surprised by the decision on the constitutionality of Obamacare.