NBC has the full story:
Senate Minority Leader Harry Reid won’t run for re-election in 2016, ending a lengthy congressional career that culminated in ten years of leadership of the Democratic Party in the Senate.
Reid announced the decision in a Youtube video, saying "We’ve got to be more concerned about the country, the Senate, the state of Nevada than about ourselves. And as a result of that I’m not going to run for re-election."
[youtube url="https://www.youtube.com/embed/MqPWTECMIQo"]
First elected to the House in 1982 and to the Senate in 1986, Reid became Senate Democrats’ top leader in 2005. He became known for his soft-spoken but tough tactical style and his fierce opposition to Republican attempts to dismantle President Barack Obama’s policies.
"On the verge of losing his own election and after losing the majority, Senator Harry Reid has decided to hang up his rusty spurs," said Ward Baker.
His retirement signals that there is no hope for the Democrats to regain control of the Senate.