I would argue that well known political persons should be completely on target for this site. It is completely within bounds to ask, "Who supports President Obama," for example, because it gets to the nuts and bolts of politics.
On topic answers could appeal to:
- polling data
- SME's analyses (I would set the bar here as a pundit writes for a periodical with a circulation of 100,000+ or is an academic that has been referenced by others)
- historical analysis
Note that it is objectively answerable as well - President Obama gets a lot of support from the young, from minorities, and from urban areas. I might rather clean all the bathrooms in Grand Central Station with my toungue than vote for the guy, but I can still objectively answer it.
Note also, I'm not saying "Candidate X is a jerk." I'm asking who supports him.
And finally, when I asked the question about the divisiveness of abortion in countries outside the United States, I got a fabulously informative answer. Essentially, I'm asking for the ability to ask the same kinds of question about foreign leaders.
As such, I would argue that if better written, personalities are completely on topic.