Bernie Sanders speaks at a campaign rally at Great Bay Community College on February 7, 2016, in Portsmouth, New Hampshire. (Photo: Andrew Burton/Getty Images)

During last week's Democratic candidates' debate, Bernie Sanders mentioned his proposal for campaign finance reform a number of times. Not only is it near the top of his reform agenda, but he sees the current campaign finance system as standing in the way of many other needed reforms. We have an economy rigged in favor of the wealthy, he says, and "sustaining that rigged economy is a corrupt campaign finance system undermining American democracy, where billionaire, Wall Street, corporate America can contribute unlimited sums of money into super PACs and into candidates.... [Y]ou're not going to accomplish what has to be done for working families and the middle class unless there is campaign finance reform." Changing the campaign finance system is the key to Sanders' "political revolution," which will empower millions of people to "stand up and fight back, demand that government ... represents us and not just a handful of campaign ... contributors."

So what, exactly, is his proposal? Given the rather unimpressive history of past campaign finance reforms, would it do any good if it passed? Sanders explains his campaign finance reform proposals in a detailed page on his website. These proposals include:

A constitutional amendment overturning Citizens United (2010), which allowed unlimited spending by super PACs, and Buckley v. Valeo (1971), which famously categorized campaign spending as political speech and thus largely without limits.

Barring that, appointing Supreme Court justices who would work to overturn Citizen United.

Passing something along the lines of the Fair Elections Now Act, which would provide public funding for candidates who are able to meet a modest level of private fundraising.

Some of these goals are more achievable than others. Passing a constitutional amendment is incredibly difficult—it's hard to see something like what he outlined above passing in three-quarters of state legislatures, no less winning a supermajority in the current Congress. A president could, of course, appoint justices who oppose Citizens United. But that's obviously a slow path to reform. Vacancies occur infrequently, and the Supreme Court must wait for cases to come to it before it can rule.

The real nugget of Sanders' reforms is the Fair Elections Now Act, and it's not a bad proposal. It's certainly more thoughtful than previous campaign finance efforts that simply sought to put caps on how much people could donate to candidates or parties. What FENA does is set a modest threshold for candidate fundraising to demonstrate their viability. For example, candidates for the House of Representatives would need to raise $50,000 across at least 1,500 donors.

If they meet this threshold, public financing would kick in. The government would provide the candidate with enough funding to run competitive primary and general election campaigns. If they wished to raise more money, they could do so in a way that magnifies the contributions of smaller donors. The government would give the candidate five times each private donation they'd received of $100 or less.

This is actually not a very radical proposal. Several states (Arizona, Connecticut, and Maine) have recently been using public financing in state legislative races. Some cities (including New York City) have been experimenting with small donor matching systems. And some of the results are encouraging, if not particularly dramatic. Small donor matching systems seem to make for a more diverse donor pool. Candidates who rely on public funding for their support spend less time fundraising and more time meeting with voters, which is nice. But it's not like such reforms have made the candidates more moderate or obviously less sympathetic to the concerns of major corporations.

It's also worth noting that small donors—the sorts of donors valorized by such reforms and generally believed to have purer souls than those who donate thousands at a single time—have their own agendas. Those who contribute small amounts tend to be more ideologically extreme than other donors. To the extent politicians would be more dependent upon them for election and re-election, such a reform could end up making government actually more dysfunctional.

That may be a legitimate price to pay, in some people's minds, if it empowers common folks against the interests of big corporations. But it's actually difficult to demonstrate that big corporations are able to get their way through campaign donations. For one thing, there are still lots of different donors on multiple sides of any issue. A politician thinking of voting one way to keep some set of corporate donors happy may quickly be angering another set of corporate donors with the same vote.

For another, it's still just really hard to find direct evidence that donations, even a lot of them, change the votes of politicians. To hear Sanders' supporters describe it, his money is pure and comes from his hundreds of thousands of supporters who want nothing more than a better future for the country, while Hillary Clinton is a shill for corporations and the military industrial complex, and her affiliated super PACs have corrupted her outlook. Isn't it interesting, then, that they voted identically 93 percent of the time they served in the Senate together? Is the hope that a complete re-structuring of the campaign finance system will make politicians seven percent less attuned to wealthy corporate interests?

The reform proposal at the core of Sanders' revolution is actually not that revolutionary, and it could actually do some good. But it's hard to see it dramatically re-structuring our electoral system, no less inducing other societal shifts. And it actually has some costs built into it, such as a potential increase in polarization. So certainly peruse and consider it, but don't expect it to bring about the revolution.