ABC News' Sunlen Miller Reports: Sen. Barack Obama, D-Ill., reacted Friday to the resignation of one of his chief rival's New Hampshire co-chair for comments he made about Obama's admitted teenage drug use.
Bill Shaheen resigned as Clinton's New Hampshire co-chair after suggesting Republicans would attack Obama for the admission if he became the Democrats' nominee for president.
Clinton personally apologized to Obama on the tarmac of the Ronald Reagan Airport before they flew to Iowa for a debate.
"I take the Clinton campaign's word that they didn't know what this guy was doing and I understand all that, but the one thing I will say is, I told my staff that if I catch you guys doing any kind of stuff like this, you're fired. Period," the Illinois Democrat told syndicated radio morning show host Tom Joyner Friday.
Listen to the interview HERE.
"What we need to do -- and I told this to Senator Clinton yesterday -- that we need to send a strong message to all of our surrogates and all of our staffs, that we don't play that," he said.
Obama said Clinton's former staffer's comment smacked of desperation.
"I take it as a compliment because it shows me that folks are getting a little worried about our campaign," he said.
"The fact that we're up in Iowa and we've now closed the gap in New Hampshire and South Carolina, that means we've got momentum and that means you're a target. What it also means is folks are excited, they're energized. I think people are realizing we've got a chance," Obama said.