By Joseph Tanfani and Seema Mehta, Tribune Washington Bureau (TNS)

Long before Ben Carson jumped into the presidential race, some of his biggest fans were scouring the country for supporters.

They set up a super PAC and began a mail campaign, eventually attracting thousands who signed up and gave money.

When Carson actually got around to running, those names jump-started his early fundraising, according to John Philip Sousa IV, great-grandson of the composer and chairman of the 2016 Committee, a super PAC backing Carson.

“It was that list that launched his campaign,” Sousa said.

The power of super PACs was unleashed by a series of Supreme Court decisions dating to 1976, including Citizens United in 2010, that opened the door to unlimited contributions to political groups — so long as they didn’t coordinate with campaigns.

This presidential cycle, that rule is being stretched like never before, as super PACs shadow candidates and take on roles once reserved for the campaign organizations themselves — even staging campaign rallies.

Many of the super PACs and the campaigns are run by a revolving door of close friends and staffers, ensuring that the two sides share a common playbook even when they avoid tripping over the vague Federal Election Commission rules banning coordination.

One Democratic commissioner at the FEC said that she is “very concerned” about the growing influence of super PACs and frustrated about the inability of her agency to do anything about it.

“These super PACS are more and more operating as arms of the campaigns,” said Ellen Weintraub, a former campaign finance lawyer. “I just find it hard to reconcile the notion that there’s no potential for corruption with super PACs raising and spending unlimited amounts of money.”

She said it was not surprising that campaigns and their allies were pushing the boundaries because the three Republican commissioners had blocked any attempt to write rules to limit super PACs.

“Our inaction is feeding a culture out there that says political actors don’t really have to abide by the rules, because if they don’t, nothing is going to happen,” she said.

The top Republican on the FEC, vice chairman Matthew Petersen, did not respond to a request for comment.

So far in the 2016 presidential cycle, super PACs have been particularly dominant among Republicans, as outside groups have raised a total of $236.5 million, dwarfing the $64.1 million in campaign accounts through June 15.

For Democrats, candidates have raised nearly $50 million while super PACs totaled $20.5 million.

Early this year, Republican Jeb Bush traveled around the country for a super PAC called Right to Rise America, helping it pile up an eyebrow-raising $103 million.

Routinely speaking in front of the super PAC’s banners, Bush sometimes stumbled when asked about his plans — saying he was running and then immediately taking it back. In his view, he never broke the law because he had not yet formally declared his candidacy.

Much of the basic political grunt work for Carly Fiorina’s campaign is being handled by a super PAC, CARLY for America, which sends staff and volunteers to shadow her on the campaign trail, setting up tables, taking down voters’ names and handing out buttons and bumper stickers.

The 2016 Committee backing Carson has paid staff in four states and volunteers that show up at his events and hand out copies of Sousa’s 212-page paperback “Rx for America,” which describes the retired neurosurgeon as “the one man who can save the America that our Founding Fathers created.”

Groups supporting Hillary Rodham Clinton are part of this phenomenon too. A rapid-response group called Correct the Record broke away from a pro-Clinton super PAC and is now working directly with the campaign. A spokeswoman for the group contends an FEC loophole means that the coordination regulation doesn’t apply to them because their work is posted only online.

Richard L. Hasen, an expert on campaign finance at the University of California, Irvine, said candidates were poking holes in the argument that, because super PACs are independent, there is no risk of corruption in unlimited donations to outside groups.

“The close relationship between super PACs and candidates this time really puts that to the test,” he said.

Many of the outside groups are run by old allies who intimately know their candidate’s thinking. Right to Rise, for example, is led by Mike Murphy, a GOP strategist who has been running Jeb Bush’s campaigns since 1998.

“He’s a good friend and I’m going to miss him,” Bush said two days before he entered the race.

Staff frequently move back and forth.

Terry Giles, a Houston lawyer, served as Carson’s original campaign chairman. He resigned in June, soon after Carson formally entered the race, so he could begin advising the super PACs — after a 120-day cooling-off period required by the FEC.

“I’ll be getting them in alignment with the message that I know Ben wants,” said Giles, who plans to meet with Sousa and leaders of two other pro-Carson super PACs. “There needs to be coordination on how the money is spent.”

After that task is done, Giles said, he will return to a role as a Carson advisor and debate coach, though without any position in the campaign. He said his plan to move back and forth complied with election laws.

He’s not alone: CARLY for America political director Tom Szold over the summer took a similar role in Fiorina’s campaign.

The super PAC representatives say it isn’t hard to avoid crossing the line on coordination. For instance, staff members at CARLY for America say they track Fiorina’s movements by checking the candidate’s schedule, posted online.

“We work hard to get our volunteers there and help the people on the ground,” said Katie Hughes, spokeswoman for the Fiorina super PAC. “We would love to help connect them with other Carly supporters.”

Sousa said his group had “bent over backward” to avoid coordinating. Sharing the list of supporters is no problem because the super PAC charged the Carson campaign a fair rate, he said.

(Los Angeles Times staff writer Maloy Moore in Los Angeles contributed to this report.)

(c)2015 Tribune Co. Distributed by Tribune Content Agency, LLC.

U.S. Republican candidate Dr. Ben Carson speaks during the Heritage Action for America presidential candidate forum in Greenville, South Carolina September 18, 2015. REUTERS/Chris Keane