This list of potential candidates for the /2018 election is highly speculative and contains names that have been mentioned as either publicly or privately considering candidacies, or worthy of consideration as candidates or recruiting prospects by the parties or interest groups. The numerical key indicating our assessment of each person's likelihood of running is obviously important, given the "long and dirty" nature of this list, which will be updated each week. (1) Announced candidacy or certain to run; (2) Likely to run; (3) Maybe; (4) Mentioned but unlikely * = Indicates Potential Retirement Current Senate Lineup: 46 Democrats 54 Republicans 2 Independents/ Other Parties Arizona Rating: Lean Republican Last Incum. Percentage: 49.7% 2016 Winner: Trump 49.5% Democrats Republicans Sen. Jeff Flake Kelli Ward, frmr. st. Sen., ’16 U.S. Sen. cand. (1) California Rating: Solid Democratic Last Incum. Percentage: 61.6% 2016 Winner: Clinton 61.5% Democrats Republicans Sen. Dianne Feinstein Connecticut Rating: Solid Democratic Last Incum. Percentage: 55.2% 2016 Winner: Clinton 54.5% Democrats Republicans Sen. Chris Murphy Delaware Rating: Solid Democratic Last Incum. Percentage: 66.4% Subscribe now to continue reading, Flexible plans & easy cancellations, starting as low as $35/month. Learn more. Subscribe now Already a subscriber? Sign in here.