I think I've come up with an idea for public campaign financing which I don't hate.
Currently, on your income taxes, you can check a box to designate $3 of your taxes to go towards the presidential campaign matching fund. That money funds all the qualified candidates who accept the matching funds. I leave that box unchecked because I want the likes of Mike Huckabee and Bill Richardson to pay their own ways.
My idea is that rather than that checkbox diverting into a shared fund, you instead have a portion of your taxes saved up, and 3 months in advance of each election you have the option of saving it for later, abandoning it into the public treasury, or designating it to candidates of your choosing.
The first variation I came up with was a $10-20 fee each election cycle to register to vote (waived if you're below a certain income threshold), which (after deducting administrative costs) is paid to the campaign funds of the candidates you designate while registering. This variation won't work, as it's
unconstitutional for good reason.
In either proposal, additional contributions and independant issue advocacy are absolutely permitted. The purpose of this proposal is to increase the portion of campaign finance which comes from the broad electorate, thus diminishing the relative influence of large donors, which is the primary goal of public finance proposals.