Campaign finance reform would be a positive way to further encourage the marketplace of ideas.When campaign contributions don't have any limits then only people with really deep pockets have a say in who does and does not get elected.When reform is in place more people tend to have a say in the process.
The problem with many theories of free speech is that they do not take into account that some people or organizations with vast resources have more ability to get their message out than others. This will always be true, however our current system where our politicians get almost all of their money from a few wealthy donors is intolerable. There should be more stringent limits on donations, and there should be state funding for all candidates who can gather different number-levels of signatures. Our government spends trillions of dollars every year, much of it wasted on corrupt projects and policies. Giving money to diverse political groups would in fact save money, since it would help fight corruption; everyone would be able to get their ideas out, leading to a better marketplace of ideas overall. And in the long-run, parties with better ideas could gain power and attempt to displace the current parties, who are unfortunately somewhat corrupt and moribund.