Or, alternatively, since voter registrations don't get changed that fast, the pollster is simply setting us up for a situation where the majority of people he samples can be called Independents.
That will allow him to discount the opinions of those with a political affiliation. That, in turn, allows the pollster to detach the resuting poll results from politics.
Trying to figure out why the pollster would want to do that, but there it is.
Actually, if you look closely at the polling, you will see that it clearly shows that those who are leaving off self-identifying as Republicans are now self-identifying as Independents.