Even before the Democrats won a 55-seat Senate majority in 2012, many analysts agreed that they were likely to lose the chamber in 2014. After all, the party would have to defend seven seats in states that Mitt Romney had won — and against a midterm electorate likely to be more favorable to the GOP.
We're hearing the reverse analysis now, after Republicans just retook the Senate. In 2016, the GOP will have far more seats up — 24, compared to the Democrats' 10. Furthermore, seven of these Republican-held seats are in states that Obama won twice, and they'll have to be defended amid presidential-year turnout:
But Democrats shouldn't get too confident. Here are five reasons why, despite the favorable map, they might not be able to retake the Senate in 2016:
1) Democrats will need a net gain of four seats to retake the chamber
Assuming that Republicans win in Alaska (still not called) and Louisiana (headed to a run-off), the GOP majority will likely end up at 54 seats — thanks to pickups in Colorado and Iowa. That makes things much, much harder for Democrats.
If the Democrats had held the GOP to a 51- or 52-seat majority, it would seem quite likely that they'd manage to pluck off a couple of competitive seats from that favorable 2016 map. But netting four or five seats (depending on the outcome of the presidential race, they'll need 50 or 51 seats for Senate control) will be more difficult for the party.
2) Defeating incumbents is usually difficult
It's not easy to defeat a Senate incumbent. Even in this wave election, Republicans will only have managed to knock off five at the most (Mark Udall, Kay Hagan, Mark Pryor, and probably Mary Landrieu and Mark Begich). As the above chart shows, the most Senate incumbents who have lost in any one cycle recently is six. Kyle Kondik of Sabato's Crystal Ball has a useful breakdown of these losing incumbents by party.
Now, those tallies may be a bit incomplete, because some incumbents who believe they might lose opt for retirement rather than another run. But, in general, the tendency of incumbents to win is well-known. So if the GOP manages to prevent retirements in potentially competitive states, Democrats will have to knock off a pretty high amount of sitting senators, historically.
3) Many of the GOP incumbents are talented
Looking more closely at the Republicans in potentially competitive states next cycle, they don't necessarily seem so vulnerable. Pat Toomey (PA) and Rob Portman (OH) have attempted to portray themselves as moderate pragmatists. The 81-year old Chuck Grassley (IA) has already run six Senate elections, and he's said he's running again. Marco Rubio (FL) and Kelly Ayotte (NH) are young and talented.
Democrats probably have good chances of defeating Mark Kirk in the very blue state of Illinois, and perhaps Ron Johnson in Wisconsin. But they'll need more wins than those.
4) Democrats' own seats aren't necessarily safe
Though the Democrats are defending a mere 10 seats in 2016, some of those are potentially vulnerable as well. Michael Bennet of Colorado can't feel too secure after the defeat of his colleague Mark Udall. Democrat Barbara Boxer is viewed as very likely to retire, which would set up the first open seat Senate contest in California in decades — sure to be an expensive and high-profile contest. And then there's Harry Reid, who has now lost his majority leader position, and could face a tough reelection fight if he opts for another run.
5) The fundamentals still don't look good for Democrats
Obama's approval remains quite bad, and independents and Republicans do not think the economy is doing well, despite improving numbers on some metrics. Unless these perceptions change — which is certainly possible, considering the election is two years off — the case for a GOP presidential candidate will look strong. And that if that candidate wins, he or she will likely have some coattails, and carry Republican Senate candidates to victory in competitive states.