"Where enough money calls the tune, the general public will not be heard."

That's what US Supreme Court Justice Stephen Breyer wrote in a dissenting opinion in a case decided by the high court in April, McCutcheon v Federal Election Commission. Federal campaign finance law limits donors to giving $5,200 to an individual federal candidate per election cycle, in addition to $5,000 annually to a political action committee. The decision struck down an overall limit on individual giving per election cycle, so before the ruling, a person could only give $48,600 to candidates and $74,600 to PACs.

Now, the sky is the limit.

Only three of Breyer's colleagues agreed with his analysis that limiting so-called aggregate contribution limits does not violate the First Amendment's free-speech protections. The conservative five-member majority once again eviscerated a decades-old campaign finance regulation, furthering its reasoning in the 2010 Citizens United v. Federal Election Commission decision that equates giving and spending money in elections to free speech.

Enter New Mexico's US Sen. Tom Udall. He introduced a constitutional amendment that would allow Congress and the states to "regulate and set reasonable limits on the raising and spending of money by candidates and others to influence elections." It would essentially overturn the Citizens United and McCutcheon decisions and strip the Supreme Court of its ability to declare "reasonable" campaign finance laws unconstitutional. [Click here for this week's print article about New Mexico legislative candidates skirting campaign finance limits]. You could read the full amendment here, but we've got a spoiler for you: It died a predictable death in the US Senate Thursday, with 54 Democrats falling six votes short of earning the necessary 60 votes to overcome a Republican filibuster. The death was predictable because Republicans in both Congressional chambers oppose the proposal on free-speech grounds. All 42 senators in Thursday's vote were Republicans. (Democratic New Mexico Sen. Martin Heinrich voted in favor of the amendment.)

Constitutional amendments are the only way to overturn Supreme Court precedent—short of the court overturning itself. Yet, getting Congress and the states to agree on a such a measure is a long shot.

To amend the Constitution, two-third majorities of both the US Senate—67 of 100 members—and US House—290 of 435 members—need to approve a joint resolution and pass it along to the states. Currently Democrats hold the Senate with 53 seats and two Independents who caucus with them, while Republicans have 33 more seats in the House.

Then, three-fourths of the states—38 of them—must ratify it with a majority in either a state legislature or state convention.

That's partly why Republicans called Udall's unlikely proposal, introduced in June, election-year rhetoric, while the New Mexico senator issued a statement saying he's "encouraged" by the "growing support" for the proposal. He pledges to continue fighting the high court's rulings. "Momentum continues to build for common-sense campaign finance reform," he says in a statement, "and I will keep leading this fight on behalf of New Mexicans and all Americans to restore our nation's founding principle—a democracy of, by, and for the people."

But to do so he'll need to play by the Supreme Court's rules.

Udall continues to pump money into his $3.4 million campaign warchest to take on Republican challenger Allen Weh, who reports $691,424 cash-on-hand. As of June 30, Udall, the self-professed campaign finance reformer, holds a $2.7 million advantage over Weh, the self-professed First Amendment protector who says the solution to money in politics is "more transparency, less regulation."

The latter is certainly transpiring, as Udall well knows. He was listed on an invite as the beneficiary for an Aug. 2 fundraiser held at the Albuquerque home of Shana and Greg Levenson. The luncheon invite suggests contribution amounts: "Victory" costs $1,000 per person; "Success" costs $2,500 per person; and "Triumph" costs $5,000 per person. That latter suggestion is $200 short of the $5,200 election-year contribution limit to candidates, an amount that less than 0.1 percent of the 310 million Americans donate per election cycle, according to the Center for Responsive Politics. Now, with the McCutcheon decision, that small group of donors can contribute the $5,200 limit to an unlimited number of political committees, which, according to Justice Breyer's logic, allows their voices to be amplified over that of the majority of Americans by buying access to candidates at fundraisers.

Mr. Udall wants to go to Washington. Again.