Obama makes birth certificate joke

President Obama's campaign speech Saturday featured a joke about what has been a sensitive topic: his birth certificate.

In criticizing Republican rival Mitt Romney's record as governor of Massachusetts, Obama told backers in Nashua, N.H.: "He raised fees to get a birth certificate, which would have been expensive for me."

Some of Obama's critics, such as businessman Donald Trump, continue to question whether Obama is an American citizen, despite his 2010 release of a birth certificate from Honolulu, Hawaii.

This past week, Trump offered to give $5 million to a charity of Obama's choice if he releases his college and passport records.

Obama responded by telling his own joke about him and Trump fighting while growing up in Kenya.

The president's joke today was added to the standard stump speech he gave in New Hampshire, one of the seven or so battleground states that will decide the election contest with Romney.

Responding to Obama's criticisms, Romney spokesman Ryan Williams said: "Today's desperate attacks are laughable coming from a president whose only plan for a second term is to recycle the failed policies of the last four years while raising taxes by $2 trillion."

Though a small state with only four electoral votes, New Hampshire could make the difference in a close Electoral College battle.