True, but the chance of passing an amendment of such a controversial topic is virtually nil, so I did not consider this as a real option. The bar for the Constitutional Amendment is very high.
A Constitutional Amendment is where the legislative effort on the issue in Congress is focussed now; if MayDay.US is successful in pushing the legislative balance farther in favor of efforts to reverse the effect of Citizen's United, I hardly imagine that the effort would shift to less powerful remedies than those that are already the focus.
> For Constitution Amendment to pass, it's not enough to get a couple of House members.
True, but so what? First, the Constitutional Amendment currently on the table in Congress has a lot more support than that (the version in the Senate has, IIRC, 43 cosponsors), and, second, a PAC aiming to increase legislative support can target both Congress and state legislatures, and, third, as the issue cannot be addressed legislatively except by a Constitutional Amendment, since the Supreme Court has already determined that legislation in this area violates the Constitution as it currently stands, so no other mechanism is meaningful.