This limits first amendment rights, so no good. What we should have is laws on the books that make it a requirement for transparency in funding: who is funding the candidates? What corporations are funding candidates? And the same goes for those in office already: who is throwing money their way? The trick here isn't to limit funding, but to make it known where the money is coming from. Citizens can then make more informed decisions about who to vote for, as this will empower us to know what ideals a candidate truly stands for.