candidates. and what is dr. carson s a pole? we have claudia in san francisco where ben carson will speak. reporter: that s right, dr. ben carson riding a wave of momentum as he brings his soft spoken style the west coast. the pioneering neursurgeon is set to speak in the common wealth club in san francisco and will take questions after. dr. carson who is absent from the spotlight in the past week will talk about a flat tax and his opposition to the iran deal and why he is be the country s next president. the retired doctor came in the last month s gop debate unknown and climb negligent polls every since and carson is in third place in new hampshire and second place in iowa behind