That's one of Bernie Sanders top priorities and I guarantee he'll bring it up during the primary debates and force the other candidates to take a stance on it
I'm under no delusion that it'll take some time, but I'm optimistic. We need 34 states to call for a convention, we have 4 so far, and this is one of the only issues in America that has total bipartisan support from the public; campaign finance reform, and that starts with overturning Citizens United & McCutcheon v. FEC.
Campaign finance reform touches every other issue we face, the current system has caused so much income inequality that average Americans are feeling it and asking wtf is going on, and it's only going to get worse. In essence, imo, the system is unsustainable, if nothing significant changes, it will reach a point where debates about the issue won't be necessary, people will take action.