US Democrats win key polls in NYC and Virginia

US Democrats have won key elections in New York City and the state of Virginia, in the first major polls since President Obama's re-election in 2012.

Bill de Blasio will replace three-term Mayor Michael Bloomberg to become the first Democrat leading New York City in more than two decades.

In the swing state of Virginia, Terry McAuliffe beat Republican Ken Cuccinelli in a tight race for the governor's seat.

Meanwhile in New Jersey, Republican Chris Christie's landslide re-election as governor is seen as boosting his chances of becoming a Republican presidential candidate in 2016.

Nada Tawfik reports from New York.