State (linked to summaries below) Incumbent Intent / Results Candidates (listed alphabetically) Senator Party Electoral history Arizona Flake, Jeff Jeff Flake Republican 2012 Incumbent running Deedra Abboud (Democratic) Craig Brittain (Republican) Jeff Flake (Republican) Doug Marks (Libertarian) Jim Moss (Democratic) Chris Russell (Democratic) Richard Sherzan (Democratic) Kyrsten Sinema (Democratic) Nicolas Tutora (Republican) Kelli Ward (Republican) California Feinstein, Dianne Dianne Feinstein Democratic 1992 (special) 1994 2000 2006 2012 Incumbent running Donald R. Adams (Independent) Jerry Leon Carroll (Independent) Michael Eisen (Independent) Dianne Feinstein (Democratic) Tim Gildersleeve (Independent) Eugene Patterson Harris (Democratic) David Hildebrand (Democratic) Charles Junior Hodge (Independent) Timothy Charles Kalemkarian (Republican) Caren Lancona (Republican) Richard Thomas Mead (Independent) John Melendez (Democratic) Douglas Howard Pierce (Democratic) Joseph Sandberg Stephen James Schrader (Republican) Steve Stokes (Democratic) Connecticut Murphy, Chris Chris Murphy Democratic 2012 Incumbent running Ann - Marie Adams (Democratic) Matthew Corey (Republican) Chris Murphy (Democratic) Dominic Rapini (Republican) Delaware Carper, Tom Tom Carper Democratic 2000 2006 2012 Incumbent running Tykiem Booker (Democratic) Tom Carper (Democratic) Chuck Boyce (Republican) Florida Nelson, Bill Bill Nelson Democratic 2000 2006 2012 Incumbent running Joe Allen (Independent) Lateresa Ann Jones (Republican) Edward Janowski (Independent) Tamika Lyles (Democratic) Bill Nelson (Democratic) Marcia Roberta Thorne (Republican) Joe Wendt (Libertarian) Hawaii Hirono, Mazie Mazie Hirono Democratic 2012 Incumbent running Mazie Hirono (Democratic) Indiana Donnelly, Joe Joe Donnelly Democratic 2012 Incumbent running Mike Braun (Republican) Joe Donnelly (Democratic) Terry Henderson (Republican) Mark Hurt (Republican) Luke Messer (Republican) Todd Rokita (Republican) Kiel Richard Stone (Republican) Andrew Takami (Republican) Andrew U.D. Straw (Disability Party) Maine King, Angus Angus King Independent 2012 Incumbent running Eric Brakey (Republican) Angus King (Independent) Zak Ringlestein (Democratic) Maryland Cardin, Ben Ben Cardin Democratic 2006 2012 Incumbent running Ben Cardin (Democratic) Sam Faddis (Republican) Richard "Rikki '' Vaughn (Democratic) Arvin Vohra (Libertarian) Debbie "Rica '' Wilson (Democratic) Massachusetts Warren, Elizabeth Elizabeth Warren Democratic 2012 Incumbent running Elizabeth Warren (Democratic) Shiva Ayyadurai (Republican) Geoff Diehl (Republican) Mary Lindstrom (Republican) Darius Mitchell (Republican) Allen Waters (Republican) Heidi Wellman (Republican) James Devine (Independent) Joshua Ford (Independent) Michigan Stabenow, Debbie Debbie Stabenow Democratic 2000 2006 2012 Incumbent running John James (Republican) Robert P. Young Jr. (Republican) Craig Allen Smith (Democratic) Debbie Stabenow (Democratic) Marcia Squier (independent) Minnesota Klobuchar, Amy Amy Klobuchar Democratic 2006 2012 Incumbent running Amy Klobuchar (Democratic) Jim Newberger (Republican) Mississippi Wicker, Roger Roger Wicker Republican 2007 (appointed) 2008 (special) 2012 Incumbent running Jensen Bohren (Democratic) Roger Wicker (Republican) Missouri McCaskill, Claire Claire McCaskill Democratic 2006 2012 Incumbent running Angelica Earl (Democratic) Josh Hawley (Republican) Claire McCaskill (Democratic) Tony Monetti (Republican) Austin Petersen (Republican) Courtland Sykes (Republican) Montana Tester, Jon Jon Tester Democratic 2006 2012 Incumbent running Troy Downing (Republican) Ron Murray (Republican) Albert Olszewski (Republican) Matthew Rosendale (Republican) Jon Tester (Democratic) Nebraska Fischer, Deb Deb Fischer Republican 2012 Incumbent running Deb Fischer (Republican) Larry Marvin (Democratic) Jane Raybould (Democratic) Nevada Heller, Dean Dean Heller Republican 2011 (appointed) 2012 Incumbent running Jay Craddock (Democratic) Sarah Gazala (Republican) Dean Heller (Republican) Bobby Mahendra (Democratic) Jacky Rosen (Democratic) Jesse Sbaih (Democratic) Danny Tarkanian (Republican) New Jersey Menendez, Bob Bob Menendez Democratic 2006 (appointed) 2006 2012 Incumbent running Lisa McCormick (Democratic) Bob Menendez (Democratic) Sean A. Thom (Democratic) New Mexico Heinrich, Martin Martin Heinrich Democratic 2012 Incumbent running Martin Heinrich (Democratic) Mick Rich (Republican) New York Gillibrand, Kirsten Kirsten Gillibrand Democratic 2009 (appointed) 2010 (special) 2012 Incumbent running Kirsten Gillibrand (Democratic) Rafael Arden Jones Sr. (Republican) David A. Webber (Republican) North Dakota Heitkamp, Heidi Heidi Heitkamp Democratic 2012 Incumbent running Tom Campbell (Republican) Heidi Heitkamp (Democratic) Dustin Peyer (Democratic) Ohio Brown, Sherrod Sherrod Brown Democratic 2006 2012 Incumbent running Melissa Ackison (Republican) Sherrod Brown (Democratic) Don Elijah Eckhart (Republican) Michael Gibbons (Republican) Josh Mandel (Republican) Pennsylvania Casey Jr., Bob Bob Casey Jr. Democratic 2006 2012 Incumbent running Paul Addis (Republican) Cynthia Ayers (Republican) Lou Barletta (Republican) Jeff Bartos (Republican) Bob Casey Jr. (Democratic) Jim Christiana (Republican) Paul DeLong (Republican) Dale Kerns (Libertarian) Bobby Lawrence (Republican) Rick Saccone (Republican) Andrew Shecktor (Republican) Rhode Island Whitehouse, Sheldon Sheldon Whitehouse Democratic 2006 2012 Incumbent running Robert Flanders (Republican) Robert Nardolillo (Republican) Sheldon Whitehouse (Democratic) Tennessee Corker, Bob Bob Corker Republican 2006 2012 Incumbent retiring Bill Bailey (Democratic) Marsha Blackburn (Republican) Larry Crim (Republican) James Mackler (Democratic) Andy Ogles (Republican) Texas Cruz, Ted Ted Cruz Republican 2012 Incumbent running Ted Cruz (Republican) Stefano de Stefano (Republican) Aaron Gwaltney (Independent) Irasema Hernandez (Democratic) Dan McQueen (Republican) Beto O'Rourke (Democratic) Dustin Ray Webb (Democratic) Utah Hatch, Orrin Orrin Hatch Republican 1976 1982 1988 1994 2000 2006 2012 Incumbent running Orrin Hatch (Republican) Mitchell Kent Vice (Democratic) Jenny Wilson (Democratic) Craig Bowden (Libertarian) Vermont Sanders, Bernie Bernie Sanders Independent 2006 2012 Incumbent running Bernie Sanders (Independent) Jon Svitavsky (Democratic) Folasade Adeluola (Democratic) Virginia Kaine, Tim Tim Kaine Democratic 2012 Incumbent running Tim Kaine (Democratic) Corey Stewart (Republican) Ron Wallace (Republican) Washington Cantwell, Maria Maria Cantwell Democratic 2000 2006 2012 Incumbent running Maria Cantwell (Democratic) Jennifer "GiGi '' Ferguson (Democratic) Clay Johnson (Independent) West Virginia Manchin, Joe Joe Manchin Democratic 2010 (special) 2012 Incumbent running Bo Copley (Republican) Scott Ernst (Republican) Evan Jenkins (Republican) Joe Manchin (Democratic) Patrick Morrisey (Republican) Paula Jean Swearengin (Democratic) Wisconsin Baldwin, Tammy Tammy Baldwin Democratic 2012 Incumbent running Tammy Baldwin (Democratic) Kevin Nicholson (Republican) John Schiess (Republican) Leah Vukmir (Republican) Mary Jo Walters (Democratic) Wyoming Barrasso, John John Barrasso Republican 2007 (appointed) 2008 (special) 2012 Incumbent running John Barrasso (Republican) State Senator Party Electoral history Intent / Results Candidates Incumbent
which republicans senators are up for reelection in 2018
Jeff Flake Jeff Flake Roger Wicker Roger Wicker Deb Fischer Deb Fischer Dean Heller Dean Heller Ted Cruz Ted Cruz Orrin Hatch Orrin Hatch John Barrasso John Barrasso