Last week the Supreme Court overturned federal limits on the total amounts that one person may contribute to candidates and political committees during a single election cycle. "The Government may no more restrict how many candidates or causes a donor may support than it may tell a newspaper how many candi­dates it may endorse," the Court declared in an opinion by Chief Justice John Roberts.

But according to Justice Stephen Breyer, who wrote a dissenting opinion that was joined by three of his colleagues, the restrictions challenged in McCutcheon v. FEC are perfectly compatible with the First Amendment, which "advances not only the individual's right to engage in political speech, but also the public's interest in preserving a democratic order in which collective speech matters." The idea that individual rights must be sacrificed for the sake of a vaguely defined collective interest reflects the dangerously broad agenda of campaign finance "reformers," who seek to shape the political debate so that it comports with their own notion of the public good.

Preventing corruption is the traditional justification for limits on campaign donations. As you might expect given his nebulous aim of "preserving a democratic order in which collective speech matters," Breyer favors a broad definition of corruption, including not just "quid pro quo bribery" (such as agreeing to vote for a bill in exchange for a donation) but also "undue influence."

While everyone understands what bribery entails, undue influence is in the eye of the beholder. On the day McCutcheon was argued, for instance, President Obama worried that it would exacerbate a problem created by the Supreme Court's 2010 decision in Citizens United v. FEC, which lifted restrictions on political speech by unions and corporations. The problem, according to Obama: too much speech of the wrong sort.

"You have some ideological extremist who has a big bankroll, and they can entirely skew our politics," Obama complained. "There are a whole bunch of members of Congress right now who privately will tell you, 'I know our positions are unreasonable, but we're scared that if we don't go along with the tea party agenda or some particularly extremist agenda that we'll be challenged from the right.' And the threats are very explicit, and so they toe the line. And that's part of why we've seen a breakdown of just normal, routine business done here in Washington on behalf of the American people."

In short, Obama thinks Citizens United was "devastating" (as he called it a few days after the case was decided) because it freed his opponents to criticize him and interfered with business as usual in Washington. Many Americans would see those as advantages. In any case, it's clear that Obama views campaign finance regulation as a way of managing the political debate and keeping it from becoming too "extremist," a rationale the Court has never endorsed and one that is totally at odds with the First Amendment's command that Congress "shall make no law…abridging the freedom of speech."

Similarly, the editorial board of The New York Times, which decries "the distorting power of money on American elections," cites the "broad ideological change" sought by "the Koch brothers" as a reason to keep the aggregate caps on campaign contributions. "To equate the ability of billionaires to buy elections with 'freedom of speech' is totally absurd," Rep. Bernie Sanders (I-Vt.) opines, while Sen. John McCain (R-Ariz.) bemoans "the undue influence of special interests" and Rep. Nancy Pelosi (D-Calif.) complains that "the Supreme Court has chosen to pour even more money into our process and our politics."

As self-financed candidates periodically discover, you cannot really "buy elections." Even if a candidate is interested only in gaining and retaining power, he has to convince voters he is worthy of their trust. The "undue influence" that worries Breyer, Obama, Sanders, McCain, and Pelosi is ultimately based on the power of speech to persuade, a power Congress is forbidden to regulate.