The only thing dumber than throwing a stone from your glass abode? Throwing a boomerang.

Someone should tell John McCain. In presidential politics, negative attacks are pretty much par for the course. As long as they're not lies--as both McCain's and Barack Obama's have been of late--then there's not much point wringing your hands, rending your garments and/or gnashing your teeth in protest. Even then, there's probably little political price to pay for misleading the electorate; it takes a lot for casual voters to punish a liar at the polls. That said, over the past week Team McCain has perfected a new kind of political attack that should offend the sensibilities of campaign junkies everywhere--simply because it's so counterproductive. First, McCain chastises Obama for committing a sin that he himself has committed. Then Obama points this out, distracting voters from his own foibles and refocusing the spotlight on McCain. For Obama, the impact of the attack is immediately negated. But for McCain it's doubled: he ends up looking both a) guilty of whatever he accused Obama of and b) totally hypocritical.

I've counted at least three of these "Boomerang Attacks" in the past few days. The first came last Friday with the release of "Nothing New," a web ad slamming Obama for not saying "whether he supported or opposed the government-backed rescue of insurance giant AIG." The point, of course, was to portray Obama as an indecisive neophyte unprepared for the presidency. A "true leader," the ad implied--a leader like, say, John McCain--would've taken a bold and unequivocal stand. The only problem? McCain was even more wishy-washy on the bailout than Obama. Asked last Tuesday on "Today" whether the government should intervene in the AIG meltdown, McCain was pretty clear. "They're on their own," he said. The next day, however--after the Fed announced it would step in--McCain had softened his stance, admitting on "Good Morning America" that "there are literally millions of people whose retirement, whose investment, whose insurance were at risk." It's not that Obama was a angel here. Unlike McCain, he played the weasely Clintonian game of distinguishing between "supporting" and "not second-guessing" the $85 million bailout, even going so far as to express outrage that anyone would confuse the two positions. It's that McCain's attack gave the Illinois senator an easy opportunity to bite back--and ultimately made McCain look worse than his opponent, not better. "On Tuesday, [McCain] said the government should stand aside and allow one of the nation’s largest insurers AIG, to collapse... despite the possibility that it would put millions of Americans at risk," Obama told a crowd of thousands at a northern New Mexico rally last Thursday. "But by Wednesday, he changed his mind." In other words, I'll see your indecision, Senator--and raise you one whole flip-flop, with a little bit of hypocrisy to sweeten the pot.

You'd think Team McCain would've learned its lesson. Apparently not. Hot on the heels of the AIG onslaught came an even more hypocritical attack from Crystal City--this one regarding Obama's ties to Fannie Mae and Freddie Mac, the failed mortgage behemoths. In a pair of ads ("Jim Johnson" and "Advice") and a speech Friday in Green Bay, Wisc., McCain pilloried Obama for associating with former Fannie Mae CEOs Jim Johnson and Franklin Raines. "While Fannie Mae was betraying the public trust, somehow its former CEO [Johnson] had managed to gain my opponent's trust to the point that Senator Obama actually put him in charge of his vice presidential search," said McCain. "Another CEO for Fannie Mae, Mr. Raines, has been advising Senator Obama on housing policy... Senator Obama may be taking their advice and he may be taking their money, but in a McCain-Palin administration, there will be no seat for these people at the policy-making table. They won't even get past the front gate at the White House."

Never mind the fact that Raines never actually advised Obama on anything. The real problem here is that McCain's campaign is swarming with 26 advisers or fundraisers who have lobbied for Fannie Mae or Freddie Mac--including nearly a dozen who lobby right now. As the Washington Monthly's Steve Benen wrote last week, "one of McCain's top policy advisers, Charlie Black, was lobbyist for Freddie Mac for 10 years, while his campaign manager, Rick Davis, lobbied to help Fannie and Freddie steer clear of additional federal regulations [and earned $2 million in the process]... Tom Loeffler, who serves McCain's campaign co-chairman, also lobbied for Fannie Mae. Aquiles Suarez, a McCain economic adviser, was a Fannie Mae executive. Dan Crippen, a McCain adviser who helped craft the campaign's health-care policy, lobbied for Fannie Mae (and Merrill Lynch). Arthur B. Culvahouse, who helped lead McCain's VP search committee, also lobbied for Fannie Mae." According to former Fannie Mae executive William Maloni, "photographs of Sen. McCain's staff... loo[k] to me like the team of lobbyists who used to report to me." Without these ties--which are far more extensive than Obama's--McCain would have every right to say that associating with officials from troubled financial institutions is a sign of bad judgment. Again, it's not like Obama's hands are spotless. But with them, McCain offers Obama an otherwise unavailable opportunity to remind voters that McCain's own judgment--at least by McCain's own standards--is worse. So much for "no seat... at the table."

With this brief history in mind, I'm betting that McCain's latest attack ad--the start of a new effort to transform Obama "into a scheming insider-urban-machine politician," according to the Atlantic's Marc Ambinder--will backfire as well. Called "Chicago Machine," it's meant to distract the media--and the electorate--from the latest economic news by resurrecting stories about Obama's ties to "unsavory" Chicago figures like Mayor William Daley, Governor Ron Blagojevich, State Senator Emil Jones and developer Tony Rezko. Leaving aside questions of whether any of these links are relevant--Obama was opportunistic and ambitious in Chicago, but "corrupt" is a tough sell--I suspect that McCain's attack has opened the door for Obama to launch a rather obvious counteroffensive of his own: on Washington, D.C. Obama could call McCain a creature of the capital--yet again. Or he could remind voters that McCain was actually, you know, involved in a real political scandal related to financial regulation (unlike Obama himself). Either way, the Republican nominee has given his rival yet another chance to say "I know you are"--in this case, part of an unethical politician culture--"but what am I?" And while Chicago may be shady, it's nowhere near as radioactive as Washington, D.C.

Beware of falling glass.

UPDATE, 3:53 p.m.: That was fast. In an email to reporters, Obama spokesman Bill Burton plays the Keating Card:

# of stories the NY Times has written over the course of the campaign about the last major financial regulatory crisis, resulting in a huge bailout, and which John McCain was centrally involved in with his political godfather Charles Keating: 0

The point here is not that McCain should be tarred with Keating. Far from it. As Ben Smith notes, "the Keating Five scandal... is hardly a secret. Indeed, the story is central to McCain's political narrative. He's called his actions a mistake, and the episode is what transformed him into a self-styled reformer." It's that accusing Obama of Chicago-style corruption provides Democrats with the opportunity to revive a scandal that otherwise would've had no reason to enter the conversation--and that could ultimately hurt McCain more than it hurts Obama.