By a quirk of fate, we may be in for some pretty turbulent Senate elections, not only this November but in 2016 and 2018 as well. Majority status could resemble a rubber band as much as anything else. It is entirely plausible that the Senate will tip back into GOP hands in 2014, return to Democrats in 2016, and then flip again to Republicans in 2018. It's all about how many — and which — seats on each side are up and exposed to losses, not to mention whether it is a presidential or midterm election. Obviously other factors could come into play, chiefly the political environment over the next four years, but also what the presidential tickets will look like in 2016, who will be in the White House come 2018, and how that person is doing.
As regular readers of this column know, Senate Democrats face a grueling challenge this year, defending 21 seats to Republicans' 15. If they don't lose any of their own seats, Republicans could win a Senate majority just by winning in states that Mitt Romney carried by 14 points or more — landslide states if there ever were any. This is a midterm election, meaning that the electorate will likely be older, whiter, more conservative, and more Republican than in a presidential year. Finally, Democrats are playing defense in a tough political environment, with President Obama's job approval, as well as his signature legislative accomplishment, the Affordable Care Act, both underwater, suffering from higher rates of disapproval than approval in the polls. Thus, Democrats have a perfect storm on their hands in trying to defend their majority this year.
Obviously, things can change over the next seven months, but aside from the three open Democratic seats that the GOP is already favored to pick up (Montana, South Dakota, and West Virginia), every other likely Democratic nominee in a competitive general-election situation has a floor vote in favor of Obamacare to defend. (Every Democratic member of the Senate voted for it, as did Reps. Bruce Braley and Gary Peters, the likely nominees for the party in Iowa and Michigan, respectively.) It's a good bet that the ACA is underwater in the polls in every state with a competitive Senate race.
However, in 2016, Republicans will go from being on the offense to being very much on defense. This is because the set of Senate seats that will be up in 2016 were last up in the GOP wave election of 2010, causing Republicans to have 24 seats to defend compared with only 10 for Democrats. Another key factor is that 2016 is a presidential year and will thus likely have a bigger and more diverse voter turnout that will favor Democrats.
What's more, seven of the GOP seats are in states that Obama carried in 2012. In Illinois, where Mark Kirk will be up for reelection, Obama won by 17 points.
Four Republicans will be on the ballot in states where Obama prevailed by between 5 and 7 points: Kelly Ayotte (New Hampshire), Chuck Grassley (Iowa), Ron Johnson (Wisconsin), and Pat Toomey (Pennsylvania). In two other states where Republicans will be up, Obama eked out narrow wins: Marco Rubio (Florida) and Rob Portman (Ohio). Of the 10 seats Democrats are defending, none went for Romney in 2012; in fact, Obama's worst margins of victory were still in the 5-to-7-point range: Michael Bennet (Colorado), Harry Reid (Nevada), and Ron Wyden (Oregon). Of these three Democratic incumbents, at least the first two can be expected to have aggressive challengers, but each last won under horrific circumstances for their party (the 2010 GOP wave), and in 2016, they will have a tailwind from the presidential turnout. On paper, anyway, the 2016 Senate elections look pretty good for Democrats, and if they head into Election Day with 48 or 49 seats, they would seem to have a pretty good chance of regaining the Senate.
Then comes 2018. It will be another midterm election, so turnout will benefit Republicans, and Democrats will have 25 seats to defend to just eight on the GOP side.
Making matters still worse for Democrats, they will have five seats up in states that Romney carried by at least 9 points in 2012. These include Heidi Heitkamp (North Dakota), in a state that voted Republican for president by 20 points; Joe Manchin (West Virginia), in a state that the GOP won by 27 points; Claire McCaskill (Missouri), which voted Republican by 9 points; Joe Donnelly (Indiana), where Romney won by 10 points; and Jon Tester (Montana), which went by 14 points for Romney. The year 2018 will be a chance for the GOP to rebound if they had a bad Senate year in 2016.
In a weirdly coincidental way, midterm-versus-presidential turnout dynamics are synchronized with exaggerated partisan Senate exposure to create the potential for a whip-sawing Senate picture, one that would at least suggest that neither party is likely to build anything remotely resembling outright control of the upper chamber — just narrow majorities. Add to that picture the likelihood that Republicans will keep their House majority at least until the 2022 election — the first election after the next redistricting — and the odds of the current political stalemate continuing remain pretty high, regardless of who wins the presidency in 2016.