The worst fears of campaign finance reformers played out in real time on Tuesday in the U.S. Supreme Court as a majority of justices appeared inclined to make another major inroad on the regulation of money in elections.

In arguments in McCutcheon and Republican National Committee v. Federal Election Commission, the deep divide on the court over First Amendment speech protection and campaign finance limits—last reflected in the 2010 Citizens United v. FEC decision—surfaced again. This time, the constitutional attack was on federal limits on the total amount of money an individual may contribute to candidates and political groups in a two-year election cycle.

With competing hypotheticals, the Roberts Court’s conservatives challenged the government’s argument that the so-called aggregate contribution limits were still needed to combat public corruption, while the moderate-liberal wing sought to bolster the argument.

The case has attracted the usual outpouring of amicus briefs by conservative, libertarian and Republican-leaning groups challenging the limits, and liberal, union, reform and Democratic-leaning organizations defending them.

President Obama commented on the case during a press conference Tuesday afternoon in which he said, “All of us should bind ourselves to some rules that say the people who vote for us are more important than somebody spending a million or 10 million or a hundred million to get us elected. We don’t know what their agenda is.” And he added that he believes the Citizens United decision, striking down restrictions on independent spending by corporations and unions, has contributed to the problems in Washington today.

In the end, the outcome of McCutcheon may depend on Chief Justice John Roberts Jr., who asked lawyers on both sides for a narrow way to resolve what he said was a serious restriction on the speech of those who want to contribute to many candidates in an election but who are hobbled by the money limit.

A consequence of the aggregate limits, Roberts said, is “telling someone who wants to contribute to more than nine candidates, he can’t contribute to the tenth. It seems a very direct restriction on much smaller contributions that Congress said do not present a problem with corruption.”

Solicitor General Donald Verrilli Jr. conceded that the contribution limits are “not free of First Amendment cost.” But, he argued, just as the Supreme Court said in its 1976 Buckley v. Valeo decision, that the burden on speech and association is limited and justified by the government’s substantial interest in preventing corruption and the appearance of corruption. He reminded the court that there are no limits on independent expenditures and individuals can spend whatever they want on that type of advocacy.

Federal law contains two types of limits on contributions by individuals: base limits and aggregate limits. Base limits restrict the amounts an individual may contribute to candidates, political parties and political committees in a given election. Aggregate limits are the total amount that the individual may contribute during a two-year election cycle. For the 2013-14 election cycle, a total of $123,200 may be contributed.

In the landmark Buckley ruling, the Supreme Court upheld both types of limits. It accepted Congress’ justification for the aggregate limits as necessary to prevent circumvention of the base limits.

However, Erin Murphy of Bancroft, arguing for the RNC and Alabama businessman Shaun McCutcheon, told the justices that there was no longer a circumvention threat because of a “multitude of more direct anti-circumvention measures” enacted by Congress since Buckley.

For weeks, organizations such as Democracy 21, Public Citizen and the Brennan Center for Justice have voiced alarm about potentially massive amounts of money that could flow into elections if the aggregate limits were lifted. A small number of the wealthiest Americans, they argued, would control the nation’s elections and Congress.

Their concern was echoed by several justices on the court’s liberal wing who engaged Murphy and later the lawyer for Senator Mitch McConnell (R-Ky.), Bobby Burchfield of McDermott Will & Emery, in a series of hypotheticals about contributions and their potential for corruption if not limited. (McConnell, a longtime foe of campaign finance limits, requested argument time).

If the court strikes down the aggregate limits, Justice Elena Kagan said, an individual could contribute more than $3.5 million “even before I write checks to independent political action committees. Are you going to say that money isn’t going to give me influence?” (The $3.5 million is an estimate of the total that could be given by an individual with base limits but not the aggregate limits.)

“No, it’s not,” Burchfield insisted. Because of regulations by the Federal Election Commission, he said, as soon as money leaves the hands of the donor “he loses control over it and the person who receives it makes the direction.”

But the money goes to a single party, Kagan said, “I could make this even worse. The speaker of the House or the Senate majority leader could solicit $3.6 million to all party members and you’re telling me there’s just no special influence that goes along with that?”

Burchfield replied, “Well, we know from the Citizens United decision, your honor, that gratitude and influence are not considered to be quid pro quo corruption.”

Justice Antonin Scalia suggested that the limits actually harmed political parties by “sapping their vitality” and encouraging “drive-by” political action committees. He also suggested that $3.5 million did not seem like much money compared to the more than $1 billion spent by parties and candidates in the 2010 election.

Scalia called “fanciful” the thought that the sense of gratitude a senator or congressman would feel for a substantial contribution to his political party is any greater than he would feel for a similar contribution to a political action committee “which is spending an enormous amount of money in his district or in his state for his election.”

Congress could change the contribution limits if it believes current limits are “deeply disabling to candidates and parties,” Verrilli said.

Kagan soon rejoined, “I suppose that if this court is having second thoughts about its rulings that independent expenditures are not corrupting, we could change that part of the law.” Verrilli replied, “And far be it from me to suggest that you don’t, your honor.”

Groups supporting the limits did not express much optimism following the arguments.

“Chief Justice Roberts did appear to be trying to thread the needle on the narrow question at hand, aggregate contribution limits and corruption,” said Lisa Gilbert, director of Public Citizen’s Congress Watch. “At the end of the day, we hope that he abides by precedent and keeps these limits at their current level. However, in positive news, the court did seem unwilling to challenge the base contribution limits, which would be a broader decision.”

Contact Marcia Coyle at mcoyle@alm.com.