No, Sen. Manchin is not up for re-election in this election cycle. His term expires in January 2017, with an election in November 2016: http://www.periodicalpress.senate.gov/reelection-2016/

Of course he's up for re-election in the sense that all congresscritters are up for re-election unless they declare otherwise. And I don't think anyone on HN would dispute "pandering" and "staying in the news!"