It looks like most of the 2012 presidential hopefuls have one thing in common: They have close ties to the people who run some so-called Super PACs.

Those are the new-fangled PACs that are allowed to raise unlimited money and can run ads supporting or attacking candidates, but are also supposed to operate independently of candidates. As the New York Times detailed Sunday, those lines are increasingly being blurred:

The groups are typically founded by the candidates' former aides, financed by the candidates' top donors and implicitly blessed by the candidates themselves. And they are quickly beginning to rival the candidates' own money operations in size and scope, setting off a fund-raising arms race that is changing the way presidential campaigns are financed and executed.

As the Los Angeles Times has detailed, Democrats and Republicans have both been aggressively using Super PACs. There are a number of Super PACs that support President Obama, which have raised $7.61 million altogether in the first half of this year, according to the Center for Responsive Politics. (For more on Super PACs and how they came to be, check out our earlier guide.)

Now concerns are growing about how independent Super PACs really are from the candidates they support. The New York Times notes that Barack Obama, John Huntsmann and Michele Bachmann all have Super PACs run by the candidates' former aides or associates.

In June, Senate Majority Leader Harry Reid sent out an email soliciting contributions to a Democratic Super PAC, with a disclaimer at the end to protect Reid from accusations of collaboration: “Senator Reid is only asking for a donation of up to $5,000 from individuals and federal PACs. He is not asking for funds from corporations, labor unions or other federally prohibited sources.” Open Secrets noted that Reid's former chief of staff and one of his long-time strategists were on the Super PAC's staff.

More recently, Mitt Romney has raised eyebrows for working closely with a Super PAC. Romney spoke at a fundraiser for the Restore Our Future PAC earlier this year, leaving the room before the leaders of the group started to discuss their plans with potential donors. The Super PAC was founded by three of his former aides.

The Restore Our Future PAC also came under scrutiny when it received a $1 million donation from a company that dissolved shortly after donating, and listed no owner or address in its corporate records. After campaign-finance watchdog groups started calling for an FEC inquiry, former Bain Capital executive Edward Conard identified himself as the donor. Romney co-founded Bain Capital in 1984 and served as its CEO until 1999.

"I think the whole controversy with regards to his contribution certainly sort of disappears when he came forward and said he was the contributor,” Romney stated after Conard identified himself. “He's been a long-term business associate and friend of mine, a contributor in the past."

Some of the Super PACs supporting Texas Gov. Rick Perry are founded by people in his inner circle, including former Perry chief of staff Mike Toomey, who co-owns a private island with Perry's campaign manager. Dan Shelley, who used to be Perry's legislative director and now runs two pro-Perry PACs, told the Huffington Post that he hasn't talked to the Perry campaign about his work, since "that's against the law."

Perry has also faced other questions that he's getting too cozy with his big donors. This week, the Houston Chronicle reported on allegations that one of Perry's big donors, Bob Perry (no relation), may have indirectly funneled $500,000 to the governor during his 2006 re-election campaign, using the Republican Governor's Association as an intermediary. If that's the case, it could be a violation of Texas campaign disclosure laws. Records of the calls became public as part of a lawsuit filed by Chris Bell, Perry's Democratic challenger in the 2006 gubernatorial race.

Under Texas law, Bob Perry was free to make unlimited contributions to Perry's campaign itself. Bell's lawyers allege that the donation was funneled through the RGA to avoid criticism, since Perry had just attacked Bell for receiving a $1 million contribution from a wealthy Texas lawyer. Perry settled with Bell for $426,000 last year. Perry's campaign and the RGA both say that they did not violate Texas law.