I doubt there's that much danger of priming here, because most people's political identification is quite well entrenched and the main effect of a question like this is going to be to call to mind that affiliation, whether or not it matches any of the options in the question.

On the other hand, I'm not quite sure why "communist" is on the list of options, especially with the explanatory text saying "for example the old Soviet Union"; there aren't a lot of advocates for Soviet-style communism around. (Last year 8 people picked this; the next most unpopular option got 35 votes, and not-answering-at-all got 30.) I doubt comparability would be badly broken by removing it.

(I'd also argue that "libertarian" is in practice a right-wing option -- e.g., libertarians tend to vote for parties of the right in preference to parties of the left[1] -- and that what's described here as "liberal" is, if you look at a broader scale than just the US, pretty much centrist. I am aware that both of these are controversial assertions, and to reduce thread-derailing I will probably not respond to comments on them. Anyway, for anyone who agrees with me the picture after removing communism would then be two right, one centre, one left.)