Politico’s story on how JD Vance won the Republican primary contains what is a striking new development in campaign finance. Vance’s campaign itself was not raising large amounts of money, but the massive contributions from Peter Thiel and others were sent to a super PAC that was supporting Vance. The super PAC leaders decided they had to substitute, in essence, for the campaign. To receive unlimited donations, the super PAC must be independent and cannot coordinate directly with the campaign. So instead they set up a public website on which they posted data and analysis that they hoped the Vance campaign would follow.

Here are some of the key passages on this from the story:

Shortly after Vance launched his campaign last summer, Thompson set up a public website where he published a trove of sensitive documents — from thousands of pages of polling data, to memos assessing the strengths and weaknesses of Vance’s opponents, to a 177-page opposition research book detailing all of the areas where Vance’s opponents might attack him. There were suggested lines for Vance to use on the campaign trail, and even guidance on how the candidate could win Trump’s endorsement.

All of it was out in the open for the world to see. But it had one intended audience: the Vance campaign.

The site — housed on the publishing platform Medium under the username @protectohiovaluesforms — allowed the super PAC to publicly convey information to the Vance campaign without breaking federal laws prohibiting coordination between big-spending outside groups and campaigns. By accessing the website, the lesser-funded Vance campaign was able to capitalize on the resources of the Thiel-funded super PAC.

The issue of how to define illegal “coordination” between campaigns and purportedly independent PACs has long bedeviled campaign finance regulation. But usually, we see the issue arise in a different circumstance: the campaign puts out publicly available information about its message, targeted voters, spending plans and the like, and the super PACs who are interested in doing their work in a way that aligns with the campaign’s strategy then follow.

This story illustrates what I call “reverse coordination” and I am not sure it’s happened on this scale before. The super PAC takes the lead: it does much of the work a traditional campaign does, makes that analysis public, and the campaign then follows the path the super PAC has laid out.

What’s going on here is implicit coordination between campaigns and super PACs, though in this case the other way around. Could Congress or the FEC ban this kind of implicit coordination through the public posting of information? That’s hard to imagine, and it would certainly raise substantial First Amendment issues.

There are many proposals to tighten up the definition of coordination — such as prohibiting figures who recently worked for a campaign from turning around and working in a super PAC supporting that candidate, or requiring super PACs to be multi-candidate PACs rather than being devoted solely to electing one candidate. But I haven’t seen proposals that would ban publishing of campaign-related information, for obvious reasons.

As long as independent spending is constitutionally protected — and it’s Buckley v. Valeo that establishes that it is — it is difficult to see how regulation could effectively limit the kind of implicit coordination, including the new form of implicit coordination, that the Vance example illustrates.