Campaign finance debate heats up ahead of 2016

Campaign finance reform is back on the political agenda.

The issue largely receded to the back burner after the Supreme Court's 2010 Citizens United decision allowed super PACs to receive unlimited donations from corporations and unions.

But the nascent presidential campaign season is changing that. Democratic presidential contender Hillary Clinton lamented the amount of money that can influence elections during a recent stump speech. Pressed at town halls, potential Republican presidential candidates Chris Christie and Lindsey Graham have offered their own solutions. And just for good measure, a Florida mailman landed a gyrocopter on the lawn of the U.S. Capitol to bring attention to the cause.

The developments are raising hopes among activists that campaign finance will be a major issue in the election.

"2016 will be a watershed election," said Craig Holman, a lobbyist for the pro-reform group Public Citizen, pointing to Graham and Clinton endorsing a constitutional amendment.

Still, changing campaign finance rules will be tough.

Barack Obama, now in office for more than six years, has disappointed those looking to change the system. Congress isn't moving on any campaign finance legislation. And thanks to recent Supreme Court decisions, donors have more vehicles than ever to influence the political process.