Hasen proposes that campaign finance reform advocates take the time now “to plan for the next Supreme Court.” We should use the indefinite waiting period to “think more about what a reasonable campaign finance regime would look like” and acknowledge that “conservatives are absolutely right that campaign finance laws can boost incumbents and stifle political competition.”

I agree with Hasen on all of that, even the last points, but I’d go even further: A reasonable campaign finance regime, one that doesn’t boost incumbents or stifle competition, could even be put in place with the existing Supreme Court. (The current Congress is another story.) The thinking he’s proposing is going on right now, and is even being tested, in systems based on the principle of “small-donor public financing.” These systems use some combination of matching funds, tax credits, vouchers, or generous public financing for candidates who show a base of small-donor support. They make it easier for candidates to run who don’t have big-donor support in order to enhance public participation and to ensure that elected officials aren’t entirely dependent on big donors or corporations, whether those donors are giving directly to campaigns or to outside groups.

The public financing systems in Arizona, Maine, and Connecticut, which have been resilient, strongly supported by the public, upheld in the courts, and used by almost as many Republicans as Democrats, fall into this category. So does the generous matching system in New York City that has the support of Governor Andrew Cuomo and a growing number of legislators, which can serve as a model for legislation elsewhere. So can Minnesota’s system, which is currently unfunded but which until a few years ago offered a quickly refundable tax credit for small contributions along with a match on the candidate side. All of these systems can be considered part of a broad experiment, and scholars are looking closely at them to see whether they change who runs for office, who donates, and ultimately whether the states’ political processes are more responsive to the public.

Legislation at the federal level has followed the small-donor model as well. Rep. John Sarbanes’Grassroots Democracy Act, for example, draws on elements from several of the successful state programs, including a refundable tax credit for small donors along with a matching program for campaigns. The Fair Elections Act similarly incorporates a combination of small donor incentives with full public financing. A voucher that would allow every citizen to contribute in the same way that she votes, long advocated by Yale Law Professor Bruce Ackerman who calls them “Patriot Dollars,” and more recently by his Harvard counterpart Lawrence Lessig, is attracting renewed interest as well.

All these systems are voluntary, and alone they don’t go too far toward controlling big money, except for the candidates who participate. But they do make it possible for candidates to run who wouldn’t be able to otherwise or who want to run independently of big money. If they’re designed well, they can help candidates be in the position to get their messages out, and at a certain point it doesn’t matter all that much if the other candidate has a lot more money or more outside money spent on her behalf. (The Brennan Center put out an excellent report in 2011 on the many positive effects of small-donor public financing.)

The big question is whether these systems can work without limits on outside money. Without limits, candidates might hesitate to participate, voluntarily limiting their own spending, if they worry about being overwhelmed by big outside campaigns. It’s also unlikely that the public will support throwing good money into a cesspool of unregulated spending for very long. If that’s the case, these systems will need backup from the kind of limits that are under challenge in the recent cases or rejected by the court in Citizens United or other cases. But even after the court rejected a feature of the Arizona system that gave candidates more money if they were attacked by outside money, the system survived, and a majority of candidates for statewide office in 2010 and 2012 participated in the system.

The 2012 federal elections offered even more evidence that small-donor systems can work. It was not that“money doesn’t matter” (a view challenged by Roosevelt Institute Senior Fellow Thomas Ferguson and colleagues here), but rather that once a candidate for the House, Senate, or lower office has reached the threshold that allows him to be heard, extra money on the other side, whether from outside groups or the opposing campaign itself, matters less. For example, all the Senate candidates hit with outside spending by the Sheldon Adelson and Koch Brothers-funded groups won reelection. If small-donor public financing can get candidates to that threshold, then limits on outside spending won’t be as important in making the system work.

That’s not to say that it isn’t worth trying to strengthen the limits that remain and to build on the broader consensus that supports disclosure. In particular, the Internal Revenue Service should enforce the law governing 501(c)(4) non-profits, which are increasingly being used as vehicles for undisclosed and unlimited campaign spending, but which are not permitted to have influencing elections as their “primary activity.” The sheer number of mechanisms by which a donor can try to influence the outcome of an election has proliferated so far beyond the old standby of broadcast advertising that it will be impossible to chase it all down.

The next generation of campaign finance reform doesn’t have to be developed in a laboratory while waiting for Scalia or one of his colleagues to retire or to encounter a higher judge. It’s being designed, refined, tested, and improved as you read this in a half dozen states and municipalities. If it works, it will lead us to a system that will moderate the influence of economic inequality on democracy while enhancing competition and strengthening First Amendment rights of free expression.