The early Capitol Hill relationship between former Speaker Newt Gingrich (Ga.) and former Sen. Rick Santorum (Pa.) has been described several ways: friendship, mentorship, rivalry — even frenemies.

“Newt recognized his talents early on,” said Rep. Jack Kingston (R-Ga.), a Gingrich supporter. “In fact, I remember one time he said to me that Santorum could well be president.”

In the 2012 GOP presidential race, both candidates have attempted to paint their time in Congress to their political advantage. Santorum criticized the former Speaker as an establishment figure unwilling to push for change on Capitol Hill, while Gingrich claims he carried the reform banner there for years before the Pennsylvania lawmaker’s first election.

Interviews with former GOP House Members reveal a symbiotic and shifting relationship during their eight overlapping years in Congress. From the House check-kiting scandal through welfare reform, neither Republican could boast about some of their key Congressional achievements without the other’s assistance.

“I think Rick had a certain amount of respect with Gingrich,” said John Brabender, Santorum’s longtime political consultant. “At the same time, he had a certain amount of frustration with Gingrich.”

When Santorum arrived in the House in 1991, Gingrich had recently become Minority Whip. The House GOP thirsted for power after almost four decades out of the majority, and Santorum quickly brought Gingrich a headline-grabbing opportunity for Republicans to point fingers at Democrats.

As part of the “gang of seven,” Santorum pushed for disclosure after USA Today reported many Members regularly bounced checks at the House bank without penalty. The scandal became known as “Rubbergate.”

The reform-minded group of freshmen picked up the House banking scandal over beers in the office of then-Rep. Jim Nussle (R-Iowa), “thinking we’d try to make a stink about it” in a few one-minute floor speeches, former Rep. Scott Klug (R-Wis.) recalled.

“Much to our collective astonishment, it took off like a rocket,” Klug said.

At first, Gingrich supported the gang of seven mostly in private, former Members said.

After all, he had to work with the check-kiting GOP Members in his own caucus as their Whip — although House Democrats accounted for most of the guilty parties. What’s more, Gingrich had 22 overdrafts in the House bank, including one for almost $10,000 to the IRS.

“It wasn’t something the Republican leadership was eager to take on,” said former Rep. John Doolittle (R-Calif.), another gang of seven member. “I’m sure they knew more about the fallout than the seven of us.”

Gingrich kept his support quiet, but he was encouraging. He autographed a front-page USA Today story lauding the gang’s reform efforts for each of the Members. Former Rep. Frank Riggs (R-Calif.), another member of the group, still remembers every word he wrote in the margin: “Change takes courage and effort. Keep up the good work. Newt.”

“I have mixed feelings,” Riggs said. “Rick showed a lot of courage in bringing the matter to light. … On the other hand, Newt has a long history of basically pushing, pressing for fundamental reform.”

As Rubbergate gained traction, Gingrich got onboard more publicly. He attended a fundraiser at the American Legion on Capitol Hill to support the gang of seven. Eventually, Gingrich took the lead among GOP leadership in beating the drum for an audit of the House bank on the floor.

“On the night where we had the key vote, [Gingrich] made the speech that summed everything up instead of the Minority Leader,” former Rep. Charles Taylor (R-N.C.) said, referring to then-Minority Leader Robert Michel (R-Ill.). “I think [Gingrich] and Santorum were friends throughout that time.”

Santorum needed Gingrich — a key ally in GOP leadership — to back his reform efforts. But Gingrich needed Santorum and the gang of seven to kick-start his campaign for the Speaker’s gavel. Rubbergate became one of House Republicans’ key arguments, along with Gingrich’s “Contract With America,” that helped remove Democrats from power in the historic 1994 elections.

But many years later on the campaign trail, the relationship between Santorum and Gingrich is hardly symbiotic. As Gingrich soars in national polls ahead of Tuesday’s Florida primary, Santorum is fading and continues to fight for relevance in the race.

As a result, the two Republicans and their supporters squabbled over taking credit for their Congressional accomplishments. In last week’s South Carolina debate, Santorum charged that Gingrich knew about the House banking scandal for years before it became public.

“You knew about it for 10 or 15 years because you told me you knew about it,” Santorum shot at Gingrich during the Jan. 19 debate. “And you did nothing because you didn’t have the courage to stand up to your own leadership.”

Former gang of seven members dispute Santorum’s recollection of this. Gingrich’s supporters said that if he knew about the check-kiting scandal earlier, he would have used it against Democrats already.

Instead, Gingrich’s supporters portray Santorum as his protégé, saying Gingrich is someone without whom the gang of seven — and Santorum’s political career — could not have flourished.

“It was Newt’s whip team that put together the so-called gang of seven,” said former Rep. Robert Walker (R-Pa.), a Gingrich backer. “We on the whip team gave them a lot of staff support, helped them attack the House bank scandal.”

Walker said Santorum used Gingrich’s Conservative Opportunity Society platform as the basis of his first House campaign. Santorum also ran his uphill bid for Senate based on Gingrich’s Contract With America, he recalled.

In 1995, Santorum was sworn into the Senate and Gingrich became Speaker. But they continued to cross paths through their work on welfare reform.

The landmark legislation proved to be Santorum’s first major project in the Senate, as well as one of Gingrich’s first big victories as Speaker. After President Bill Clinton vetoed two versions of the bill, he signed welfare reform into law in August 1996.

“Can Newt take credit for it? Well, he was Speaker, so I guess he can,” said former Rep. Clay Shaw (R-Fla.), a key player in the welfare legislation battle. “Can Rick? There’s a lot of people who can take credit for it.”