On Friday morning, Senate Minority Leader Harry Reid took to Twitter to announce that he won't be running for reelection.

My life’s work has been to make Nevada and our nation better. Thank you for giving me that wonderful opportunity. https://t.co/dwy2rDWYhO — Senator Harry Reid (@SenatorReid) March 27, 2015

Reid entered the Senate in 1987, and served as minority whip, majority whip, minority leader, and majority leader. He led the institution during the financial crisis and shepherded the Patient Protection and Affordable Care Act to its passage. He was, at times, a traditionalist struggling to manage a Senate that had collapsed into dysfunction. He initially fought both Republican and Democratic efforts to weaken the filibuster before reversing himself in 2013 and leading a successful campaign to exempt most nominations from the filibuster — a rule change he managed with a simple majority.

In January, Reid suffered an accident while exercising that broke four of his ribs and left him with a bruised face and an eyepatch. In his video today, he mentions the injuries. "This accident has caused us to have a little downtime," he says. "I have had time to ponder and think."

Reid says he won't run for reelection again, then continues: "Senator McConnell, don't be too elated. I'm going to be here for 22 more months, and you know what I'm going to be doing? The same thing I've done since I first came to the Senate. We have to make sure the Democrats take control of the Senate again. I feel it is inappropriate for me to soak up all those resources on me when I could be devoting those resources to the caucus."

Reid goes on to list the reasons he's not retiring: "The decision I have made has absolutely nothing to do with my injury. It has nothing to do with my being minority leader. And it certainly has nothing to do with my ability to be reelected, because the path to reelection is probably easier than any time I've run for reelection."

That may be true, but it's also true that the path to reelection for Reid is probably easier than it is for any other Democrat in Nevada. Reid's seat, which is up in 2016, will be more of a toss-up because he's retiring. But that's likely part of why Reid announced his retirement so early: it gives the Nevada Democratic Party more time to choose his replacement and get their campaign together.

Most insiders think New York's Chuck Schumer is the likeliest choice to lead Senate Democrats after Reid steps down. But Illinois's Dick Durbin, who is currently the minority whip, is also a possibility.