Polling the New Hampshire Primaries: What Happened?

At the Huffington Post, John Zogby writes:

There was no shortage of polls going into the New Hampshire primary in 2008 and it looks like we all missed the mark on the Democratic side. This will require a lot of scrutiny in the coming days and weeks, but here are some initial thoughts on what has been happening:

1. According to the exit polls, 18% of the voters said that they made up their minds on primary day. That is just an unprecedented number. I have polled many races, especially close ones, where 4% to 8% have said they finally decided on their vote the day of the election and that can wreak havoc on those of us who are in the business of capturing pre-election movements and trends. But nearly one in five this time?

2. It looks like the always feisty voters in both Iowa and New Hampshire have rejected pre-election coronations. In the case of Iowa, Democratic voters said that Mrs. Clinton is not inevitable, while in New Hampshire they were not ready to endorse the Obama train without checking the engine.

3. The compressed schedule of the two events may have had an impact. Normally the winning candidate gets an initial big bounce out of Iowa, and then plateaus. Then the next primary race begins. With less than five full days, Obama got his bounce in New Hampshire, then the settling down period began on the last day -- under the radar screen.

4. My polling showed Clinton doing well on the late Sunday night and all day Monday -- she was in a 2-point race in that portion of the polling. But since our methods call for a three-day rolling average, we had to legitimately factor the huge Obama numbers on Friday and Saturday -- thus his 12 point average lead. Unfortunately, one day or a day-and-a-half does not make a trend and we ran out of time.

5. Going into the New Hampshire primary, we certainly did see Clinton holding on to a significant lead among women and older voters. But we were focusing on Obama's massive lead among younger and independent voters. We seem to have missed the huge turnout of older women that apparently put Clinton over the top.

6. We expected that Obama would receive the lion's share of independents and drain the Republican primary of these voters. It now appears that, perhaps with a sense that Obama had a lock on the Democratic side, independents felt free to vote on the Republican side and reward their hero, John McCain.

We will pour through the data and try to come up with something more definitive, but those are my early observations. There is much speculation that Senator Clinton's crying incident may have offered voters -- especially women -- a peek at the human side of someone who is often seen as scripted. I think she also scored points during the ABC debate Saturday night when she declared, amid a discussion about the country's desire for a change in direction, that electing a woman would represent a big change in itself. Her numbers did go up in that last 24-hour period.

On the other side, most of us did a whole lot better coming close to the numbers on the Republican side of the aisle. But this is one of those cases that remind us that pre-election polls are guides to voter attitudes and shifts. All things considered in this and other cases, we pollsters still do a creditable job.