Sports coaches don't like excuses. "Excuses are like assholes," goes a favorite coach saying, "Everybody's got one and they all stink." That's the basic sports coach response to any attempt, valid or otherwise, to contextualize an event whose outcome the coach disapproves of.
Social scientists tend to think in more sophisticated terms. They try to examine data in a complete ways, isolating independent variables so they can make a decent judgment about whether X caused Y, or some other combination of events had responsibility.
This distinction came to my mind when I read Megan McArdle's rebuke to people who assert that President Obama inherited rather than created the projected budget deficit:
[A]t some point, Obama has to take responsibility. Listening to his defenders reminds me of those people who sit around whining about how their Dad was really distant and critical . . . I mean, fine, you apparently had a rotten childhood, but Dad can't get come and get you off the couch and find you a girlfriend and a better job. Girls and employers get really creeped out if they try.
Whatever George W. Bush did or did not do, he's no longer in office, and doesn't have the power to do a damn thing about the budget. Obama is the one who is president with the really humongous deficits. Deficits of the size Bush ran are basically sustainable indefinitely; deficits of the size that Obama is apparently planning to run, aren't. If he doesn't change those plans, he will be the one who led the government into fiscal crisis, even if changing them would be [sob!] politically difficult.
I have a serious question for the people who are mounting this defense: at what point in his presidency is Obama actually responsible for any bad thing that happens? Two years? Five? Can we pick a date for when bad things that happen on Obama's are actually in some measure the responsibility of one Barack Obama, rather than his long gone predecessor? And then stick with that date?
The question of to whether Obama created or inherited the deficit is an objective one. The answer is clear:
As I've said before, this does not answer the question of responsibility. One could argue that, having inherited a terrible budget situation, Obama is obligated to do more than he has to date to clean it up. That is a fair subject of debate. The problem is, accusing Obama of failing to go far enough to clean up the mess he inherited doesn't have the ideal political punch. It's far more useful for conservatives to implicitly or explicitly blame Obama for creating the budget mess. The tea party events are not filled with protesters freaked out that Obama has taken only meager steps to alleviate the fiscal crisis he inherited.
That's why conservatives have reacted so ferociously to any attempt to contextualize the fiscal reality. Bring up facts about who created the deficit, and they want to start talking about how graceless it is, or how you're a pathetic whiner. Some principle of social etiquette will demand that these facts be excluded from the discourse. Coach McArdle doesn't want to hear your pansy excuses, variable X! Now get in there and stop letting variable Y kick your ass!