Beacuse I'm from the future and my job is to assassinate the president. If you kill me I won't return to my time and it will alter the time line thus resulting in a rip in the space time contineum and releasing the mole people on to the world. But, I'm one step ahed, they already got out in the future they were released by the president's body guards when they shot me so I had to come back in time to stop the mole men, so if you kill me the mole men will not only get out into the world but will now have the ability to breed thus creating an army of super mole men that would take over the world and all future will be runed then another rip will open and then cuthulu will come out and make us all his monkey slaves!!!!! So, long story, short..... don't kill me.