@Tor-EinarJumbo gives what I think is the correct answer, but I would like to add another that addresses @SebastianRedl's comments.
Here is the complete data from the poll. The question about Agrabah had only three responses: 'support bombing', 'oppose bombing' or 'not sure'. Presumably a response of 'I've never heard of that country.' was filed under 'not sure'.
The 41% figure given for Trump supporters is of all responses. So the full response list is:
- 41% support
- 9% oppose
- 51% not sure (sic. Rounding errors)
The figures of around 50% 'not sure' is fairly constant across all the Republican primary supports, with the happy exception of George Pataki, whose supporters returned a 100% 'not sure'. Presumably George Pataki scores high among people who listen to questions and know the names of countries.
The 50% 'not sure' is also fairly constant across all other demographics.