Who is Marjorie Tench from Deception Point and what is their importance?

Marjorie Tench is the senior adviser to President Herney. She is a tall, very thin and scary-looking woman, who constantly smokes. She is very politically savvy and wants to ensure that President Herney wins re-election. She knows that NASA did not discover the meteorite but is instrumental in setting up PODS to make the discovery.