300 dead, an organized attack on an entire base. That would be awful hard to cover up. There may have been an attack, usually a base like that gets a mortar or two or more lobbed in on a daily basis (rarely
). Usually someone who pulls up with a buddy on the back of a motorcycle, or vehicle, the passenger jumps out, launches a mortar, and they drive off before retaliating fire can pinpoint them and tear them to shreds.
Living on a base out there, when there's a loud boom, most everyone switches the TV to one of the network news channels to get whatever details they can. An entire base being attacked in an organized fashion resulting in more than 1/10th of the entire amount of deaths in the whole war would be out across the news in less than 5 minutes.
I'm sure someone lobbed some mortars into the base that day, there may have been fatalities, we might be lied to about the number of fatalities, but election or no, 300 dead is too much to not make it all over the news. Unless of course it was 300 Iraqis dead, we (Americans) only seem to care about our own, and seem to care less about any other death toll that may be out there.