My take on this is that on any given day Obama receives at least 25 nutball letters containing suspicious substances. Such a distraction can be ordered-up on any day he chooses.
The media needed a southern “Republican” whipping boy in the wake of the Islamist attacks. Except he posed with his Christian Democrat bumper sticker...
The facility that checks this mail coming in to the gub'mnt has sniffers ~ and other things ~ and they're pretty sensitive.
You could probably rub a caster bean on a letter and they'd pick it up.