Thomas Lindenfeld, a Washington-based political consultant hired to help run U.S. Rep. Chaka Fattah's 2007 mayoral campaign, had concerns.

Concerns, early on, over his candidate's ability to raise money. Concerns, in the days before the primary, over Fattah's dire polling numbers. Concerns, after losing the race, about how Fattah would pay back the late-in-the-game $1 million debt Lindenfeld had incurred on the congressman's behalf.

But to allay each worry, the campaign consultant told a federal jury Wednesday, Fattah offered the same response again and again.

"He said he'd take care of it," Lindenfeld said, testifying on the third day of Fattah's federal racketeering conspiracy trial.

Lindenfeld, a linchpin witness in the government's case, was unequivocal when asked who had arranged what prosecutors have described as an illegal $1 million loan to the Fattah for Mayor campaign. It was equally clear, he said, who had endorsed the scheme to pay it back using stolen charitable and federal grant funds.

"We spent it according to instructions from the congressman and on what he wanted it spent on," the campaign consultant said. "I thought if he was responsible for paying it back, he should be directing how it was spent."

In clear and matter-of-fact tones, he recalled checking in with Fattah at each step of obtaining and repaying the loan. Under questioning from Assistant U.S. Attorney Eric Gibson, he described why he did not hesitate to stake his entire business as collateral.

"I had the word of the congressman" that he would pay it back, Lindenfeld said. "I felt that was adequate."

And yet, in the campaign consultant's retelling, Fattah was careful never to make his intentions explicit.

Lindenfeld pleaded guilty in 2014 to wire fraud charges, admitting his role in what has become the central scheme in the government's case against Fattah. His testimony came as part of a cooperation deal reached in a plea agreement with prosecutors - a fact the congressman's lawyer, Mark Lee, is likely to stress Thursday when he cross-examines Lindenfeld.

Lee already has accused Lindenfeld and another former campaign aide turned government cooperator, Gregory Naylor, of executing the loan scheme on their own without Fattah's knowledge.

"This is a case about two men who cut deals with the federal government to keep them out of federal prison," the lawyer said during his opening statement to the jury this week.

Lindenfeld came to Fattah's 2007 mayoral campaign with an established political pedigree. After leading a series of successful campaigns in New Jersey in the '80s, Lindenfeld went on to become director of elections for the Democratic National Committee. His former business partner, David Axelrod, later would become the architect credited with President Obama's 2008 election strategy.

Fattah's polling numbers in the early days of the mayoral race suggested an easy path to victory, but Lindenfeld sensed early on what would be the congressman's largest hurdle.

"I am concerned . . . whether you can assemble a fund-raising support base that has not been part of your political history and prowess up to now," he wrote to Fattah in an early 2007 email shown to jurors Wednesday. "You have routinely been one of the least proficient fund-raisers in Congress."

Lindenfeld's fears were borne out as the race became a crowded five-man jockeying match against tough candidates including the self-funded millionaire businessman Tom Knox and eventual winner Michael Nutter.

A late-race cash scramble

As Fattah's early poll numbers slipped with only weeks left in the primary, the congressman had no money for crucial TV advertising.

It was then that Fattah introduced Lindenfeld to Al Lord, the wealthy CEO of student-loan giant Sallie Mae. At the congressman's request, the consultant said, he met with Lord at his Washington-area office in May 2007, although the two did not discuss money at the time.

"I called the congressman after to tell him what had happened, and ask him what to do next," Lindenfeld said. Within days, Lord offered to loan $1 million to Lindenfeld's consulting firm with the intention to fund Fattah's ad buys.

Still, it wasn't enough to prevent Fattah from finishing the 2007 race in a disappointing fourth place. Lindenfeld said he immediately began to worry about how soon Fattah would give him the money to pay Lord back.

"I told [Fattah] we have a debt we need to pay," Lindenfeld said. "He told me, 'I'll take care of it.' "

Prosecutors spent much of Wednesday tracing the complex method they say the congressman used to steal $600,000 to cover the outstanding debt and hide the source from federal auditors. Through a series of additional witnesses, they sought to demonstrate that the money came from two education nonprofits Fattah founded and was funneled through sham contracts to a for-profit firm owned by a Fattah family friend, Robert Brand.

Brand, who also has been charged in the case, has denied that his firm, Solutions for Progress, was used as a conduit in the alleged debt-repayment scheme.

But Lindenfeld told jurors Wednesday that Brand contacted him out of the blue eight months after the mayoral race with an unusual offer to pay him $600,000 up front for a meeting to discuss potential marketing work for Brand's firm.

Lindenfeld had only worked for political candidates and had never been paid such a large sum by any client before doing any work. Yet, he said, he knew immediately what Brand's proposal was about.

He accepted the money, he said, but did no work for Brand or his firm.

"That meant to me," said Lindenfeld, "that this was the way Congressman Fattah was going to repay his debt to Al Lord."