President Barack Obama talking with Stephen Colbert of The Colbert Report during a taping of the program in Lisner Auditorium at George Washington University in Washington. It was supposed to be a joke. “Are you still president?” comedian Stephen Colbert asked Barack Obama earlier this month. But the question seemed to speak to growing weariness with the president and skepticism that anything will change in Washington during his final two years in office. Democrats already are checking out Obama’s potential successors. Emboldened Republicans are trying to push aside his agenda in favor of their own.