The program they might have used is Flash. They took pictures of themselves then placed the politicians heads on their bodies.

Watch this for more details.

Flash is a great program. People use it for a dozen kind of different animations.
Akuma vs Chameleon
Sticks Demacia vs Noxus
Left 4 Speed
Different styles, same program

However, this is the only program I know to do this. Their might be others.