From a Comment at Newsbusters

The Postal Service created a stamp with a picture of President Obama on it.
The Postal Service noticed that the stamp was not sticking to envelopes.
This enraged the President, who demanded a full investigation.
After a month of testing and $1.73 million in congressional spending, a special Postal Commission presented the following findings:

1. The stamp is in perfect order.
2. There is nothing wrong with the glue.
3. People are spitting on the wrong side .