Depends on the types of people who are likely to give up their phone number for national political polling reasons, and in that subset, I'd think that is hardly random.
They don't go out and canvass for phone numbers first. If they don't include cell phone numbers it's possible to bias more towards older persons, but that wouldn't invalidate the survey either.
It's true, I've never taken a statistics course. But, if the experts tell me a 0.0003% sample size is fine so long as it's the RIGHT 0.0003%, then I guess I'll have to concede the point.
