Coping with Political Polling Overload

Accuracy

As the candidates stabilize, voters firm up who they'll vote for (if anyone), and the samples grow more detailed, polls naturally become increasingly accurate. At six months, they average +/- 5.8%; four months it's around 4.8%; down to 1.7% a week before election.

Turnout

There are approximately 245 million potential voters in the US. Only ~150 million of those are likely to cast a ballot, and ~58 million of those show up at the primaries to determine who will appear on our ballots. So if you're politically active, encouraging turnout has the greatest impact, not arguing conversion.

Our two major parties also have different turnout rates. In lower turnout years, Republicans tend to win (as we saw in the 2014 Senate majority change), while higher turnouts give Democrats an edge. See image (thanks for the share, Chris).

Aggregates

No single methodology is perfect—the best picture tends to come from multiple sources. Sites which track polling:

• HuffPost Pollster
• RealClear Politics
• FiveThirtyEight's Pollster Ratings
• PollingReport

Many thanks to Chris Jackson at Ipsos/Reuters for an engaging talk at the Puget Sound Research Forum. If you ever have the opportunity to hear a full time pollster talk about their methodology, it's well worth it.