ALBANY  As Caroline Kennedy embarked on a tour of upstate New York this week, camera crews and reporters in tow, the state’s attorney general, Andrew M. Cuomo, was announcing a $2.7 million settlement with the operator of an illegal dump in Lackawanna.

Ms. Kennedy ended up on the cable television networks, in national newspapers and on blogs everywhere. Mr. Cuomo got a story in The Buffalo News.

Since he returned to the state capital two years ago, Mr. Cuomo, son of a former governor, has thrown himself into his job, tackling issues large and small. And he has softened the in-your-face style that earned him enemies years ago.

So when it became clear that the Senate seat held by Hillary Rodham Clinton would become open, Mr. Cuomo restrained himself from overt campaigning and retreated to the background. That left the stage to Ms. Kennedy, who has marched out front and become the candidate everyone is talking about  and the favorite for the appointment.