Extra: Watch the video of Richardson's withdrawal from Commerce consideration at SFR's new blog, SFReeper.com

So far there’s no proof Gov. Bill Richardson had a hand in a suspected “pay to play” scheme involving a state contractor, California-based CDR, and campaign contributions from its founder, David Rubin.

Nevertheless, the US Justice Department’s investigation into CDR aborted Richardson’s appointment as President-elect Barack Obama’s commerce secretary.

Even if it turns out Richardson’s administration did nothing wrong, there are some questions that need to be answered in the meantime. For starters:

Did the labyrinthine financial deals the state entered under his watch with companies like CDR actually save taxpayers money? Or is this more of the alchemy that brought down Wall Street last fall?

The New Mexico Finance Authority claims the state saved more than $28 million, thanks to CDR’s help in creating an artificially low “synthetic” fixed interest rate on $1.6 billion in transportation bonds.

But so far, no state officials have bothered to explain how that math works.

CDR is the kind of company with which the average person never does business, but which would not exist without public tax dollars. It works for institutions all over the country that need big loans to fund big endeavors—in this case, the Rail Runner.

What CDR sells, essentially, is advice: Borrow from this bank, not that bank.

“They’re kind of the traffic cop on the deal; they’re a middleman that goes and finds the best underwriters,” Richard Williamson, Southwest bureau chief for The Bond Buyer newspaper, says.

There is no evidence yet that CDR gave bad advice on its $1.5 million deal to study financing for Richardson’s transportation projects. But state officials should have had reason to worry.

Last April, CDR ran into trouble over a New Mexico project with the state’s troubled Region III Housing Authority. In 2003, the Housing Authority hired CDR to find money to develop lease-to-own housing for poor families in Bernalillo County and beyond.

CDR hooked the Housing Authority up with Société Générale, or SocGen, a large French bank recently entangled in a fraud scandal.

As The Bond Buyer reported in April 2007, IRS investigators found an “improper financial relationship” between CDR and SocGen—kickbacks, basically.

Which raises another question:

Did CDR’s troubled history with the Housing Authority lead any state agency to review CDR’s work on the transportation bonds? And if not, why not?

New Mexico Department of Transportation spokesman SU Mahesh said he would answer questions only by e-mail and then failed to respond by SFR’s press deadline.

Finance Authority Chairman Stephen Flance wasn’t aware of the IRS investigation into CDR’s work for the Housing Authority. “In retrospect, we’ve all learned more about CDR than we wanted to—but I didn’t know that,” he tells SFR.

Flance directed further questions to Finance Authority General Counsel Reynold Romero, who said he could not discuss details of CDR’s work, given his own lack of financial expertise. Instead, Romero sent a prepared statement, dated Aug. 29.