Welcome to Pollapalooza, our weekly polling roundup.

Poll(s) of the week

The Iowa caucuses are just two days away, and FiveThirtyEight’s forecast shows a pretty wide-open race there: No candidate has more than a 36 percent chance of winning the most votes.

[Our Latest Forecast: Who will win the Iowa caucuses?]

There’s still time for a few more Iowa polls to drop and shake up the race, but it would be somewhat anomalous: There have not been as many Iowa surveys this cycle as in past cycles, especially in what is historically the most frequently polled time period — right before the caucuses. In fact, if we look at the final month of polling in each nomination contest since 1980 in which Iowa was contested, the 2020 Democratic race has had fewer polls than any other cycle this millennium, with the exception of 2000.

This cycle’s had fewer Iowa polls leading up to the caucuses Number of surveys of Iowa conducted in the final month before contested caucuses, 1980 to 2020 Cycle Party Caucus date Number of Iowa polls in month before caucuses 2020 D Feb. 3* 11 – 2016 R Feb. 1 25 – 2016 D Feb. 1 23 – 2012 R Jan. 3 27 – 2008 D Jan. 3 23 – 2008 R Jan. 3 22 – 2004 D Jan. 19 15 – 2000 D Jan. 24 6 – 2000 R Jan. 24 6 – 1996 R Feb. 12 6 – 1992 D Feb. 10 2 – 1988 D Feb. 8 10 – 1988 R Feb. 8 7 – 1984 D Feb. 20 1 – 1980 D Jan. 21 1 – 1980 R Jan. 21 1 – *Data for 2020 through 6 p.m. on Jan. 30. Figures include tracking polls but do not include polls from pollsters banned by FiveThirtyEight. Source: Polls

Back in the day, there weren’t that many pollsters who surveyed the Iowa caucuses. In the 1980 and 1984 cycles, the Des Moines Register did almost all the public polling there, and there wasn’t very much of it before the caucuses. But over time, other pollsters have started to measure voting preferences among caucusgoers. The number of surveys started to balloon in the late 2000s, when more than 20 polls were conducted of both the Democratic and Republican caucuses in the final month before the 2008 contest. This rate of polling largely remained stable through the last cycle, when between 23 and 25 polls were completed in the 31 days prior to the caucuses. This time around, however, the number of polls has dropped to 11, and will likely end up at or below the number of polls conducted during the last month of the 2004 Democratic race.

Why the sudden drop-off? One possible explanation is that the impeachment of President Trump has competed for valuable polling resources (this certainly seemed to be the case in December). But beyond other stories pulling attention, polling firms are facing a whole lot of challenges these days. Response rates for polls conducted by live phone calls have continued to fall and more people are relying entirely on cell phones, which means pollsters often have to manually call cell numbers rather than use auto-dialing technology to reach landlines. Combined, these challenges make traditional polling more expensive. And while online polls are filling in some of the gaps, they’re still something of a new frontier and are also more likely to herd — a phenomenon in which pollsters produce results that mirror the results from other firms, particularly toward the end of a race — which reduces their value.

Additionally, getting a good sample of likely caucusgoers isn’t easy: Caucus turnout tends to be lower than primary turnout because it’s a more time-consuming process. This means it’s even costlier to poll in Iowa because you have to dial a bunch more numbers to contact enough likely caucusgoers. Perhaps due in part to increased costs, some major pollsters — Fox News, Marist — haven’t polled Iowa once this cycle, while other outlets that used to release their own polls have joined together to sponsor them, such as CNN and the Des Moines Register.

[Our Latest Forecast: Who Will Win The 2020 Democratic Primary?]

In fact, it’s entirely possible that the only surveys we’ll get in the final run-up to Monday’s caucuses are the vaunted Iowa Poll, conducted by Selzer & Co. on behalf of CNN, the Des Moines Register and Mediacom, and a final survey from Emerson College. As it stands, the most recent Iowa polls we have were in the field through Tuesday, so if there have been late shifts in voter preferences in the latter half of this week and into the weekend, it may be tough to detect them in advance. Those sorts of late swings in voter choices have certainly happened before — if there’s one thing we know about Iowa, it’s more of a surprise when there isn’t a surprise or two.

Other polling bites

Trump approval

According to FiveThirtyEight’s presidential approval tracker, 42.9 percent of Americans approve of the job Trump is doing as president, while 52.7 percent disapprove (a net approval rating of -9.8 points). At this time last week, 42.0 percent approved and 53.8 percent disapproved (for a net approval rating of -11.8 points). One month ago, Trump had an approval rating of 42.6 percent and a disapproval rating of 53.0 percent, for a net approval rating of -10.4 points.

Generic ballot

In our average of polls of the generic congressional ballot, Democrats currently lead by 5.7 percentage points (46.9 percent to 41.2 percent). A week ago, Democrats led Republicans by 5.5 points (46.8 percent to 41.3 percent). At this time last month, voters preferred Democrats by 6.5 points (47.4 percent to 40.9 percent).





What is the difference between a primary and a caucus?