I wonder if this actually means anything long term. Hopefully the winds of change (against the major parties) is occuring.
I believe that as the two parties become more and more polarized, they'll also continue to shrink.
But that doesn't mean they'll vote for a third party. Being an Independent and voting for third parties will be two different things.
That's true to an extent, like in my own case, for example. I obviously have absolutely no loyalty to or identification with either of the main parties, but will still vote for one or the other if there are no
viable alternatives. Yet if a major independent or third party candidate did emerge - who did have a chance of winning (such as Perot in '92 or Bloomberg in '08 for example) - I'd happily vote for them, as I'm sure would millions of others.
What this poll is illustrating is that more and more people are apparently thinking the way I do.