My goal with these diaries (previous entries: The House, The Senate (2018) has been to look at both the opportunities for, and the limits to, potential Democratic gains in Congress and in state legislatures based on recent electoral performances. While the 2012 Obama coalition retained the presidency and kept the Senate in Democratic hands, it’s less clear (to me, at least) that it represents a realistic and sustainable formula for winning and keeping the House. On the Senate side, 2018 is a sufficiently tough map that even Obama’s own 2012 numbers would yield a net loss of four seats if replicated for our Senate candidates, and Clinton's 2016 numbers would result in a veritable massacre with Republicans holding a 61-39 majority. To have even a remote chance of winning a Senate majority in 2018, Democrats will need all their incumbents to get re-elected (including five in states that went for Trump by more than 15 points), pick up Nevada and Arizona, and then squeeze one more win out of the group of Mississippi, Nebraska, Tennessee, Texas, Utah, and Wyoming — and even then, they'd just have a 51-49 edge. A more realistic “best-case scenario” is a probably a 50-50 tie, in which all the Democratic incumbents survive and Nevada and Arizona flip.
So what about 2020? Once again, I start with three data points for every state in play: the Democratic Senate candidate’s performance in the previous cycle (in this case 2014), Obama’s 2012 numbers, and Clinton’s 2016 numbers. I also look at what would happen if Democrats improved upon these starting points by 5 percentage points. Finally, I look at a “best cases combined” scenario in which Democrats win all of the seats that they would carry under any of these six scenarios.
I am assuming that any state in which the same party has won by more than 10 points in all three elections under consideration (President 2012, Senate 2014, President 2016) will not flip. That means that the following seats are not included in the table of possible outcomes below:
Democrats (6): Coons (DE), Durbin (IL), Markey (MA), Booker (NJ), Merkley (OR), Reed (RI)
Republicans (14): Sessions (AL), Cotton (AR), Risch (ID), McConnell (KY), Cassidy (LA), Cochran (MS), Daines (MT), Sasse (NE), Inhofe (OK), Graham (SC), Rounds (SD), Alexander (TN), Capito (WV), Enzi (WY)
Here are the numbers on the remaining seats (right-click on this and select "View Image” to see the table full-size):
So even in the best of all possible worlds — and by that, I mean one in which Democrats take the Senate seat currently held by Susan Collins in Maine and repeat Mark Begich’s 2008 miracle in Alaska — Democrats would be poised for a net gain of five seats, and maybe six if you throw in Georgia (which just barely falls short of going Democratic in the “Clinton+5%” scenario). Some other key points:
1) We might think that Team Blue would have more pickup opportunities in 2020, given that this is the brutal 2014 cycle coming back around, but several of the Republican gains that year came from the retirement or defeat of Democratic incumbents in solid-red states. Barring scandals, exceptional candidates, or a true Trumpocalypse, the chances of the seats in Arkansas, Louisiana, Montana, South Dakota, and West Virginia returning to the Democratic column just aren’t very high.
2) Colorado, Iowa, North Carolina, and possibly Maine ought to be prime targets depending on whether Collins runs again and how toxic the Republican brand may be by 2020. Next on the list would probably be Alaska (which leans Republican but has an unpredictable independent streak) and Georgia. Kansas is only even included above because I chose to count independent Greg Orman’s numbers towards the Democrats. As for Texas, John Cornyn is less controversial, and less likely to face a bloody primary, than Ted Cruz and thus probably safer.
3) While the real disaster of the “Clinton Coalition” scenario would come in 2018, it wouldn’t be much better in 2020, still leaving the Senate with a filibuster-proof GOP majority even if Collins were replaced by a Democrat. The Obama Coalition of 2012 would leave the Democrats in better shape — as would either presidential coalition with an additional 5-point swing — but still short of a Senate majority.
So the bottom line is this: Democrats have to win some light-red and even solid-red Senate seats if they want to be back in the majority in the Senate by 2020. A wave might help them pull this off and/or narrowly capture the House, but as we saw in the aftermath of 2006 and 2008, waves don’t necessarily lead to durable majorities, and when they break, they can leave Democrats deeply vulnerable to a redistricting nightmare (as happened in 2010). In my next diary, I’ll look at the numbers for the state legislative chambers that are likely to play a major role in redistricting, then move on to some closer analysis of key states and possible strategies for maximizing Democratic gains.