Yes. What we have seen is a classical demonstration of the Overton Window Principle. And what they are often trying to do with polls like this (as propaganda tools) is the equivalent of the man below pushing the window of what is "acceptable" to the Left. This has been going on relentlessly (by the Left) with some success for decades.

I figured that out when obama was running against romney.
We had a democrat running against a communist.
What a choice.