Talk Elections

How are primary polls made for states holding caucuses or closed primaries?
It would be illogical to survey random persons.

Pollsters screen people by their likelyhood to vote or ask them if they have voted in previous caucuses. If these people say 8/9/10 on a scale, you have a good sample of who is likely to vote.

Actually, to speed processing and keep costs down to acceptable levels while maintaining sufficient numbers of respondents to give provide statistical validity, a number of pollsters use panels.

These panels allow comparison of choices over time.

You both have to admit that polls only make sense when they are about open primaries.

Surveys about caucuses and/or closed primaries are rather useless.

Caucuses are notoriously hard to poll. Polls for the Iowa Caucus are often very far off.

Until the last few days, that is.  In 2008, Zogby (of all people!) managed to nail both of the Dem and GOP caucuses in Iowa in his final poll there.  ARG (!!) also nailed the GOP side (but screwed up on the Dems), while Insider Advantage nailed the Dems (but didn't poll the GOP side).

not to mention.  Selzer & Co.

They call random people, ask their partisan affiliation, often apply a likely voter screen (as mentioned above), then only actually poll the people who are likely to vote and properly registered to do so.