Because he can lie and then repeat it without flinching:
First, the embassy in Cairo–not the White House, not Foggy Bottom, but the embassy–released its statement denouncing (not by name) the makers of the inflammatory film about Mohammed. That was around noon local time Tuesday.
Then the attacks happened.
Then, last night, came Romney's statement criticizing the Obama administration for its allegedly "disgraceful… first response" being "to sympathize with those who waged the attacks."
But: the attack hadn't happened! That first embassy statement was apparently issued because word was circulating about possible violence, and the embassy was trying to quell it.
Then the Obama administration distanced itself from the original embassy statement, and then Romney issued last night's statement.
So here's Romney now, at 10:18 am, now that he must surely know this chronology, still defending his statement from last night and criticizing Obama for defending the attackers.