Lessig's amendment would provide public funding for federal elections. It would limit private contributions to candidates for federal office to $100. It would give Congress the power to limit, but not ban, independent political expenditures within 90 days of an election. (Citizens United struck down a similar provision in the McCain-Feingold campaign finance law.)
It would provide that the First Amendment could not be construed "to vest in any non-natural person any unalienable constitutional rights."
In other words, the rights under the First Amendment could not be interpreted to apply to a corporation.
Congress would be obliged to establish a federal elections agency to enforce the provisions of the amendment. The agency would have standing to enforce the amendment in the federal courts and to file actions against Congress.
Finally, the First Amendment could not be construed to limit legislation that would flesh out the amendment, except "to assure content and viewpoint neutrality."
Presumably that would prevent Congress from enacting laws to ban some viewpoints but not others. Also, the First Amendment could not be construed "to limit the equivalent power of state or local legislation enacted to regulate elections of state of local officers."
The best and most important idea in Lessig's amendment is public funding of election campaigns. That would eliminate federal officials' dependence on big contributors and those donors' stranglehold on Congress and the presidency. Yet, it would still give people a chance to support candidates of their choice through $100 contributions.
It would not eliminate corporations' voices in the public square, so they could defend their interests, but it would give Congress power to limit them during the late run-up to elections.
That's a decent compromise and a good starting point for discussions leading to an eventual amendment.
Tomorrow: Apply amendment to states