Does the inclusion of all adults explain why they keep getting such Clinton favorable polls? Or is there something else going on? (Not saying they're wrong, but they're definitely a lot more Clinton favorable than other polls.)
In almost all recent presidential elections, adult polls are much more Democratic than RV polls or LV polls. Everyone knows that.
Mostly because non-registered and non-voting adults are strongly leaning-Democratic.
A poll before the 2012 GE has shown that unregistered and non-voting adults would back Obama over Romney by a 60-10 margin, with the rest undecided.
Considering that only 55-60% of adults will vote next year, it makes no sense to poll all adults for a presidential election.
Polling all adults makes only sense if you want to poll issues like crime, gun rights, gay marriage or health care etc., because these issues involve every adult.
Obviously, Hillary is not ahead by 15-20% nationally - but still ahead by a good amount.
I'd say if you have an adult poll showing Hillary ahead by 10 nationally, you can shave off 2% for RV results and another 2-3% for a likely voter poll.
