For instance, it seems likely that Obama has already suffered a rhetorical defeat. Whatever his faults, President Bush got to say one thing that the American people always appreciated: After 9/11, he kept us safe from a terrorist attack on the homeland. If Hasan acted as a Jihadist terrorist and not a disgruntled psychiatrist, Obama can't even make the same claim about his first year in office.
More substantively, Obama has had the luxury of exploiting his predecessor's success. His actions on Guantanamo, his mea culpas for America to the Muslim world, etc., have only been possible in a political environment absent domestic terrorist attacks. As it stands, Hasan may have been a one-off, an isolated incident. Let's hope that's the case, but let's not delude ourselves that this is likely.
Yet, if we see more of this sort of thing, the underpinnings of Obama's national-security posture may well disintegrate. His reputation for flexibility notwithstanding, the record shows that he is, in fact, implacably ideological when it comes to his core beliefs. If terrorism drives the country rightward, he may well choose to stand his ground. That's what he's done with the domestic crisis. While the country has been screaming for Washington to concentrate on fixing the economy and the unemployment rate, Obama and his party have rigidly focused on their health care schemes and cap-and-trade -- which, even if they work, will do nothing to fix joblessness in the near future.
Conversely, if the "Hasanity defense" prevails, and the left convinces the country -- or even itself -- that the shootings were a tragic byproduct of two unnecessary wars, the president will still be in a bind. Particularly among Obama's core supporters, the notion that violence only begets more violence is as popular as it is untrue.
Early reports suggested that Hasan was driven to his murder spree out of frustration with Obama's refusal to pull out of Iraq and Afghanistan fast enough. If Obama's base believes that line of argument -- which is essentially a "blame Bush" argument -- it will only intensify their opposition to escalation in Afghanistan. If Obama goes ahead with escalation anyway, the prospect of "LBJ redux" increases.
If the majority of Americans had thought in 2008 that the war on terror was a top priority, they wouldn't have voted for Obama. It only makes sense that if the war on terror once again becomes a top priority, they'll most likely regret their vote.