Few issues the Supreme Court addresses arouse more controversy than its rulings about campaign finance. This week’s ruling in the case of McCutcheon v. Federal Election Commission is likely to prove as controversial as its 2010 decision in the Citizens United case.

In McCutcheon, however, as in Citizens United, the court is correct: the First Amendment protects the fundamental rights of citizens to participate in the political process — by speaking out themselves, by associating with others to express political messages, and by contributing to political campaigns.

These First Amendment rights, like all our fundamental rights, are not absolute. Government may restrict our rights when doing so is the only way to accomplish vitally important goals.

The court has long held that whenever any one donor gives a large amount of money to a single candidate, there is a risk that the candidate will, in effect, sell him- or herself to the biggest donor.

The most direct way we combat such corruption is with laws against bribery, but Congress also has chosen to guard in advance against the risk of bribery — and also against the appearance or possibility of bribery — by limiting to a relatively modest amount of money ($5,200) the amount any one person can give per election to the same candidate for election to federal office.

In McCutcheon, the Supreme Court reaffirmed its 1974 holding in the landmark case of Buckley v. Valeo that such contribution limits are, indeed, constitutional. Similarly, in Citizens United, the Court reaffirmed that corporations and labor unions may not directly contribute to political campaigns, while holding that those groups have the right to speak out about political issues.

At issue in the McCutcheon case was whether Congress may, consistently with the First Amendment, limit the aggregate amount of money any one donor gives to a number of candidates. Under the old limits, a wealthy donor interested in politics could have given the maximum contribution to nine federal candidates, but not to a 10th candidate.

The government argues that the aggregate limits are needed to fight political corruption and the appearance of political corruption. But the aggregate limits don’t do anything to make individual candidates less beholden to individual donors. If none of the first nine contributions a wealthy donor makes is corrupting, how is the 10th contribution different? Or the 11th? Or the 20th?

The dissenters in the McCutcheon case argue, as they did in Citizens United, that Chief Justice John Roberts has a too-limited conception of what counts as political corruption. They insist that big money in politics damages the integrity of our political institutions. As Justice Stephen Breyer puts it in the dissent: “Where enough money calls the tune, the general public will not be heard.”

The dissenters’ hostility to big money in politics is understandable, but misplaced.

Political scientists have been trying for decades to show that money decides elections, but what they actually have discovered is pretty modest and lends no support to the idea that “money calls the tune” in our elections. Voters decide elections.

It is true that a relatively unknown challenger needs to spend a lot of money to become known, but once the challenger becomes well known, further spending is much less effective. Incumbents tend to be well known at the start, and popular incumbents generally don’t need to spend all that much to win, especially when they attract only weak challengers. Where both campaigns have sufficient funds to get their messages across, there is no decisive advantage to spending more.

For all the anxiety the Citizens United decision caused, there is no good reason to think all the new political speech it unleashed changed the outcome of any particular election.

Although money doesn’t decide elections, it still might make us uncomfortable for a different reason: big donors get more access to and attention from politicians.

That’s true, but that fact paradoxically makes our system more democratic, not less. Politicians will always have a limited amount of time to spend meeting constituents. And, even if there were no private money in politics, they still would have good reasons to pay more attention to powerful and influential persons — big employers, property developers, labor leaders, media figures — than to ordinary people.

The system of private funding of campaigns enables individuals who care a lot about certain issues, even if they are not big employers or union bosses, to make their political opinions public.

And the fundamental premise of our democracy is the more voices, the better.

Joseph R. Reisert is associate professor of American constitutional law and chairman of the department of government at Colby College in Waterville.