Obama defends need for federal rules in inauguration speech

"Together, we discovered that a free market only thrives when there are rules to ensure competition and fair play," he said before a crowd of hundreds of thousands gathered on the National Mall. 

He later returned to the topic, acknowledging a division between the two parties.

"Progress does not compel us to settle centuries-long debates about the role of government for all time, but it does require us to act in our time," he said.