Winning a majority vote in Congress is obviously far easier and quicker than winning a 2/3d's vote in Congress for the proposed amendment plus winning the ratification vote in 38 states. If the former is barely conceivable, the latter is totally inconceivable, no more than wishful thinking.
There has not been a constitutional amendment proposed and adopted since 1971, before the modern era of money in politics started in 1976 with the creation of the Court's "money=speech" gimmick. The last amendment (#27) was adopted over 200 years after it was proposed. The ERA, the equal rights for women amendment proposed by Congress in 1972 at the tail end of the last era of reform, was the last progressive movement for a constitutional amendment. Though it would have been of direct benefit to a majority of voters, the ERA ratification campaign which was vigorous and successful up to 1975 slowed to a halt after the era of money in politics began in 1976. The ERA fell three states short of success when the period for ratification expired in 1982.
Money gets any constitutional changes it needs from the New Gilded Age Court of the Roberts 5, and has the power to stop any they do not need. There were no amendments passed in the original Gilded Age. Similarly there have been and will be none proposed and ratified in the New Gilded Age.
A constitutional amendment to expand democracy could not be enacted until after legislation is first passed to get money out of politics, just as the progressive era amendments (##16-19) followed the T. Roosevelt-era campaign finance reforms.
A constitutional amendment related to money in politics would be superfluous after passing strong comprehensive legislation to get the Court out of elections and money out of politics. If after the necessary legislation is enacted some unforeseen reason arose to also consider necessary a constitutional amendment on this issue, that would be the time to consider the matter. Now is not the time. There is no reason now to consider or even talk about a constitutional amendment which is a hypothetical exercise at best, if not pure fantasy.
4. Proposals for a constitutional amendment are Counterproductive.
There is danger in undertaking a strategy that is sold as if it is a solution, but can quickly be seen to be at best a very incomplete solution and at worst no solution at all. Such a campaign diverts energy from working on the practical and effective solution that the country desperately needs; it diverts energy to what on its face appears impossible from an approach that appears barely possible if there were total unity and focus by supporters of democracy. A national movement that would dedicate its collective vote to this single issue of enacting a comprehensive law that can credibly promise to get money out of politics could succeed. History shows that only a 10-20% minority of committed voters could win such a law. There is no reason to make a constitutional amendment such a single issue because it can make no such promise to get money out of politics even it it could succeed.
if a constitutional amendment were to somehow succeed, it could create cynicism when it is proven to be ineffective. Thereby it might use up the one last chance citizens may have for peacefully reclaiming democracy in the US. This could lead to disaster since solutions to issues as serious as global warming, perpetual war, peak energy, the monetary system and economy -- one could summarize without over-dramatizing, the survival of civilization itself -- are all at stake in the issue of money in politics.
History shows that a constitutional amendment cannot succeed in the current political context. If it proves necessary to deploy all available political capital just to get legislation enacted, there would be none left over to pursue wasteful fantasy.
5. Advocacy of a constitutional amendment is dangerous
Irrespective of the availability of time and energy to waste on a misguided idea and still get the necessary law passed, advocacy of the need for a constitutional amendment is dangerous. This is because of its impact on the anticipated future debate over legislation in Congress.
The main, perhaps only effective, defense Congress can make to sidestep efforts to force enactment of legislation to get money out of politics would be: Congress is sorry, they would love to help, but they cannot do that because a constitutional amendment is necessary to deal with the Supreme Court.
We know that is wrong. But arguing the point in public is not easy. This is an area where Congress itself as an institution can claim expertise. Taking on an attack against the contents of the law is one thing. Congress has no particular expertise on getting money out of politics that others do not have. Congress has notionally been trying for a century and has hopelessly failed. It is clearly time for someone else to try their hand at drafting the prohibition of money in politics. But arguing this issue of constitutional structure and separation of powers is another thing. The separation of powers issue will be much more difficult to argue with Congress than the substance of the law.
Giving a corrupt Congress help by having the people opposed to money in politics actually endorse the very argument most useful to defeat the necessary legislation could pretty much deliver the fatal blow. People tend to stick with the first idea they hear. Advocacy of this bad idea will only make it more difficult to persuade natural allies of the effort to get money out of politics. It will require additional resources to re-educate allies that only a law is actually necessary after they have already been told the contrary by sources they should be able to trust -- but cannot.
A wily Congress guided by their corporate paymasters might even actually adopt the constitutional proposal and then let it languish as the plutocrats buy enough state legislatures to kill it off in 38 states. This process could waste another decade, or century, depending on the time Congress allows for ratification.
People advocating a constitutional amendment are playing right into the hands of the plutocrats and helping them make what would be their strongest argument against comprehensive legislation. This could ensure that we never get the only reform that is actually possible and at the same time sufficient. There is not enough margin for error to dismiss this risk as unimportant.