The last submission was met with positive/encouraging comments and a little skepticism, but now we have individuals overwhelmingly complaining that this is a "democrat PAC", a "leftist cause", or that it is somehow infringing on free speech rights. This is all absurd. A "democrat PAC" would not give you the option of limiting your pledge only to Republican candidates. The disgust with the influence of money in politics is not a "leftist" thing--there is just a minority trying to make it another left vs right thing by instilling the usual tribalistic hatred (most of the right hates money in politics just as much as the left does and knows how badly they are screwed by it). And the reforms the Mayday PAC supports do not infringe on free speech rights unless you believe there should be no equality to free speech--that the size of one's wealth should make one's voice much more likely to be heard.
As for the skepticism of whether or not it will work (assuming you think it's a problem in the first place--if not, enjoy your plutocracy):
First, what do you propose as an alternative? Unless you're advocating for a revolution, the solution needs to work within the system itself. Americans are very concerned about the influence of wealth in politics, but in order to transform that concern into a change in policy there need to be promising alternative candidates running on that issue (the current selection of candidates are quite reticent about it and rarely act on it because they know it threatens their re-election). Candidates that would actually like to remove the corrupting influence of wealth in politics cannot compete because one needs a lot of money to run a meaningful campaign (and the reforms supported by Mayday give such candidates a means based on support at local levels--e.g. matching funds systems). Therefore, these candidates rarely get any media attention and thus very few even know they exist or have any confidence in their success. What Mayday is trying to do is give candidates running on an issue that many Americans are concerned about a fighting chance within a system whose design is antithetical to resolving that issue. I'm all ears to your alternative solutions.
Second, while the skepticism is warranted, it is redundant. There is no solution to this problem that won't be unbelievably difficult in practice--Lessig is calling it a "moonshot" for a reason. If you look at each solution in isolation, all of them seem unreasonable and they always will until one of them by chance stumbles upon success. But this does not mean you should not act. Some solutions are less unreasonable than others and I believe Mayday PAC is one of them because it is one of the few that are working with the constraints and realities of the system in mind. And as a "kickstarter" it has been designed to reduce the risk to you as a supporter--the worst that can happen is that they raise $12 million dollars, the candidates they support are duds, and you lose $20. In the other negative case, you get to keep your $20.
But given the pent up disgust with politicians being unresponsive to the concerns of everyone except the large donors, I think Americans will respond very well to compelling candidates that make the issue of money in politics a top priority (and yes, "compelling," among other things, means well-financed--even if indirectly through a small dollar funded Super PAC) and whose financial backing does not compel them to act otherwise.