A Sunlight Foundation analysis of filings from campaigns and and outside groups found that a leadership PAC founded by former Florida Gov. Jeb Bush, as well as super PACs supporting former Hewlett-Packard CEO Carly Fiorina and Democratic candidate Hillary Clinton have each swapped consultants, staff and vendors with their respective campaign committees.

Months before announcing his candidacy, Bush was personally fundraising for his super PAC “Right to Rise,” a move Bush advisers said was legal — despite rules prohibiting coordination between super PACs and official campaigns — because he still had not determined if he would be running for office. But expense information filed with the Federal Election Commission show that much of his campaign’s senior staff were drawing regular checks from “Right to Rise PAC,” an identically named leadership PAC founded by Bush, months before the formal launch of his campaign. Other necessary campaign infrastructure, like media and polling consultants also drew large checks.

Christine Ciccone has been the chief operating officer for the Jeb Bush campaign since April, according to her LinkedIn profile, though campaign finance records show that Right to Rise PAC paid her more than $40,000 over the same period. On June 22, one week after Jeb Bush officially declared his candidacy, she even received a $1,630 check from Right to Rise PAC as well as a $1,332 check from the official campaign.

The pattern extends to many of Bush’s senior campaign team, who collected checks from Right to Rise PAC for months until joining the official campaign after his June 15 announcement, including his current director of digital content, head of voter engagement, Hispanic communications director and body man.

In addition to sharing senior staff, Right to Rise PAC and the official Bush campaign have also made large payments to common vendors.

Bush’s campaign has paid FP1 Strategies — which names Bush campaign manager Danny Diaz as a founding partner — $350,000 for media production according to its FEC reports. But Right to Rise PAC has also paid FP1 Strategies $380,000 for media and political strategy consulting.

In cases like this, media firms are supposed to have a firewall set up, so that “there’s no communication between the people working on the PAC and the people working on the campaign,” said Larry Noble, senior counsel at the Campaign Legal Center. “It’s a dangerous game to get into, frankly, because it could show evidence of coordination.”

FP1 Strategies did not respond to multiple requests for comment.

“Active vendors need to make sure that they do not compromise independence,” said Ken Gross, the lead lawyer at Skadden, Arps for political law, who previously headed the FEC’s enforcement division. “These are uncharted areas, and the first time we’re seeing them prominently in presidential campaigns.”

Both the leadership PAC and the campaign also paid the same amount, $5,935.43, in consecutive months for rent to Edgewater Corporation of Florida, a Tallahassee real estate company that, according to tax records, appears to own one office complex in Tallahassee.

Fiorina’s campaign, which is reportedly working very closely with her super PAC, CARLY for America, has paid a number of fundraising and financial consultants that her super PACs have also used. The campaign gave Conservative Connector, an email list rental service, $63,000; the super PAC paid it $42,000.

Two campaign staffers, Deputy Policy Director Casey Enders and finance head Jessica LaBerge, also collected paychecks from CARLY for America before joining the official campaign.

On the Hillary Clinton campaign, Sunlight identified two staffers who previously worked at American Bridge 21st Century, a super PAC supportive of Clinton that also launched Correct the Record, the David Brock-founded, rapid-response organization. Correct the Record has made clear its plans to coordinate directly with the Clinton campaign because of a public information exception to the FEC’s rules on coordination. One staffer, Melissa Cantrell, is currently head of media research for the Clinton campaign, while the other, Patrick Burgwinkle, is the campaign’s Iowa press secretary.

Despite the apparent cozy relationships between official campaigns, supportive super PACs and other outside groups, little can be said to be definitively improper or legally prohibited since the perpetually deadlocked FEC has given little guidance on appropriate conduct of super PACs. According to a Washington Post report, the FEC has never opened an investigation into illegal super PAC coordination since the groups first made an appearance on the political stage in 2010.

But despite the apparent impossibility of action, these interactions flout the spirit of existing laws, campaign finance watchdogs like Larry Noble say. “These are supposed to be independent groups. The Supreme Court’s concept of independence was not this concept that people can go back and forth and play these games.”