I’m tired of hearing about the USC Dornsife/Los Angeles Times tracking poll.
I’m tired of hearing about the poll from Donald Trump fans such as Reince Priebus, Matt Drudge and Donald Trump himself.1 They frequently cherry-pick that poll because it consistently shows much better results for Trump than the other surveys. As of Tuesday morning, for example, the poll showed the race as virtually tied — Hillary Clinton 44.2 percent, Trump 44.0 percent — even when the national poll average has Clinton up by about 6 percentage points instead.
This has been a fairly consistent difference between this poll and most others. Take the LA Times poll, add 6 points to Clinton, and you usually wind up with something close to the FiveThirtyEight or RealClearPolitics national polling average. What’s the source of the LA Times poll’s Trump lean? There are good “explainers” from The New York Times’s Nate Cohn and Huffington Post Pollster’s David Rothschild. Long story short: The poll’s results are weighted based on how people said they voted in 2012. That’s probably a mistake, because people often misstate or misremember their vote from previous elections.2
The poll does some other things differently also, some of which I like. For instance, it allows people to assign themselves a probability of voting for either candidate instead of saying they’re 100 percent sure. And the poll surveys the same panel of roughly 3,000 people over and over instead of recruiting new respondents. That creates a more stable baseline and can therefore be a good way to detect trends in voter preferences, although it also means that …