How proposed Democratic caucus rules make polling even harder, and how we crafted our best shot

The Iowa caucuses are arguably the most difficult assignment for any pollster. That is because relatively few people attend them, and people can, and do, change their minds in the caucus room. …

Next year, a lot will change. The Iowa Democratic Party is finalizing rules that will add a new universe of participants to the mix. Six virtual caucuses will be held in an effort to make the first-in-the-nation contest more accessible to those who might not be able to schedule several hours on a February Monday evening to take part in person. …

Our aim in designing this poll was to best capture the opinions of likely in-person and virtual caucus participants today, then apply the processes that will be used on caucus night. We offer this detailed explanation in the interest of full transparency. CONT.

J. Ann Selzer (Selzer & Co.), CNN