<P> State Representative Jim Newberger is running for the Republican nomination . </P> <P> One - term Republican Senator Roger Wicker won re-election with 57% of the vote in 2012 . He was appointed in 2007 and won a special election in 2008 to serve the remainder of Trent Lott's term . He will be 67 years old in 2018 . He is running . </P> <P> Jensen Bohren is seeking the Democratic nomination . </P> <P> Two - term Democratic Senator Claire McCaskill was re-elected with 55% of the vote in 2012 . She will be 65 years old in 2018 . She is running . She is being challenged in the Democratic primary by Angelica Earl . </P>

What democrats are up for reelection in 2018