He was referring to the 100...he was either misqouted or someone left off a zero.
Neither the $10 bill (Alexander Hamilton), nor the $100 bill (Benjamin Franklin), picture a former president.
I saw the tape. The movement is (was really, I think this momemt was its death-knell) for reagan on the 10. He was talking about the 10.
The point, as someone else said, is the 100 also doesn't have a president on it. Its all about the Benjamins.