<Tr> <Td> Arizona </Td> <Td> Jeff Flake </Td> <Td> Republican </Td> <Td> 2012 </Td> <Td> Incumbent retiring . New senator to be elected . </Td> <Td> Eve Reyes Aguirre (Green) Martha McSally (Republican) Kyrsten Sinema (Democratic) </Td> </Tr> <Tr> <Td> California </Td> <Td> Dianne Feinstein </Td> <Td> Democratic </Td> <Td> 1992 (Special) 1994 2000 2006 2012 </Td> <Td> Incumbent renominated . </Td> <Td> Kevin de León (Democratic) Dianne Feinstein (Democratic) </Td> </Tr> <Tr> <Td> Connecticut </Td> <Td> Chris Murphy </Td> <Td> Democratic </Td> <Td> 2012 </Td> <Td> Incumbent renominated . </Td> <Td> Matthew Corey (Republican) Chris Murphy (Democratic) </Td> </Tr> <Tr> <Td> Delaware </Td> <Td> Tom Carper </Td> <Td> Democratic </Td> <Td> 2000 2006 2012 </Td> <Td> Incumbent renominated . </Td> <Td> Robert Arlett (Republican) Tom Carper (Democratic) </Td> </Tr>

Who is running for united states senator 2018