said by Jason Levine :

Sarcasm aside, that's actually the real reason. "Spent $6 billion to rebuild some roads and bridges" isn't a eye catching campaign item. "Spent $6 billion hunting down and capturing terrorists intent on destroying America" is. The latter is likely to woo voters than the former so that's how the politicians spend our money. They only care about these "non-sexy" items when something catastrophic happens. (In which case, it suddenly becomes politically "sexy" to care about it.)