Now, onto the Charles Keating affair, which the Times explained last February in its otherwise tainted piece about McCain’s alleged affair with a lobbyist.

During Mr. McCain’s four years in the House, Mr. Keating, his family and his business associates contributed heavily to his political campaigns. The banker gave Mr. McCain free rides on his private jet, a violation of Congressional ethics rules (he later said it was an oversight and paid for the trips). They vacationed together in the Bahamas. And in 1986, the year Mr. McCain was elected to the Senate, his wife joined Mr. Keating in investing in an Arizona shopping mall.

Mr. Keating had taken over the Lincoln Savings and Loan Association and used its federally insured deposits to gamble on risky real estate and other investments. He pressed Mr. McCain and other lawmakers to help hold back federal banking regulators.

For years, Mr. McCain complied. At Mr. Keating’s request, he wrote several letters to regulators, introduced legislation and helped secure the nomination of a Keating associate to a banking regulatory board.

By early 1987, though, the thrift was careering toward disaster. Mr. McCain agreed to join several senators, eventually known as the Keating Five, for two private meetings with regulators to urge them to ease up. “Why didn’t I fully grasp the unusual appearance of such a meeting?” Mr. McCain later lamented in his memoir.

When Lincoln went bankrupt in 1989 — one of the biggest collapses of the savings and loan crisis, costing taxpayers $3.4 billion — the Keating Five became infamous. The scandal sent Mr. Keating to prison and ended the careers of three senators, who were rebuked by the Senate Ethics Committee in 1991 for intervening. Mr. McCain, who had been a less aggressive advocate for Mr. Keating than the others, was reprimanded only for “poor judgment” and was re-elected the next year.

McCain’s experience with the Keating affair is significant, relevant, and important, because it reveals his attitude on how the banking industry should be governed.

A few weeks ago, Bill Press at The Hill put it thusly:

McCain co-sponsored legislation relaxing regulations on savings and loans and allowing them to gamble investor funds on certain highly risky financial ventures. Sound familiar?

For his role in aiding Keating, McCain received only a reprimand for “poor judgment” from the Senate Ethics Committee. But, ever since, the “Keating Five” has been the symbol of how much influence money can buy in Washington. And McCain, having learned nothing from the experience, then turned around and repeated the same tricks on Wall Street.

In 2000, McCain supported legislation authored by Sen. Phil Gramm that forbade federal agencies from regulating financial derivatives that greased the skids for passing along risky mortgage-backed securities to investors. Today we’re suffering the consequences.

Gramm’s legislation was the key. Without it, AIG could never have veered from the solid ground of life insurance onto the shaky ground of sub-prime mortgages. And John McCain championed that legislation.

So just to sum up, Obama-Ayers is irrelevant because Obama wasn’t involved in any wrongdoing; McCain-Keating means a lot because McCain was reprimanded, and because it exemplifies the dangers inherent in his deregulatory economic philosophy. Not equal. Apples and oranges.

Today, New York Times columnist David Brooks joined the herd in equating Ayers and Keating:

Today, leaders around the world have to figure out how to stabilize economies amid volatile global capital flows. … This is the test. This is the problem that will consume the next president. Meanwhile, the two candidates for that office are talking about Bill Ayers and Charles Keating.

Alas. We should be talking about Keating, and not about Ayers. There are substantial parallels between the resolution of the Keating mess and the current bailout, wherein the federal government stepped in to absorb losses on behalf of S&L banks then, and mortgage lenders, now.

The old adage is the those who don’t learn from history are doomed to repeat it. The moral of the Keating scandal is that McCain is guilty of this very sin. Having seen firsthand the harm of regulation, he could have actually sounded the warning bells —not just claim he did as a stump speech.

Katia Bachko is on staff at The New Yorker.