You already got some great pointers regarding this from the other posters, but I would like to add that a lot of high profile politicians have at least some questionable or controversial aspects to them, to their past etc. So I would be very careful, unless you know for sure that the politician in question has no controversial views of any kind, has never been linked to anything people could feel strongly about and so on. I would also advise against it unless there is a real, proven reason for the politician to recommend you, as there are politicians that recommend a lot of people for a lot of things, as has already been mentioned, so it makes sense that a recommendation like that might seem a bit suspicious.
All that said, however, one of the candidates
ARINGO (
aringo.com) worked with this year had a very low GMAT but worked with us on his application and used a known member of parliament in his country as a recommendation, and that worked for him! (Hard to say how much the recommendation affected the end result, though)
If you want, you can always PM me with more information about the politician in question, and I could try to look them up and give you a more specific opinion based on what I find.
Also keep in mind that the letters of recommendation are not identical from school to school, as each school requires you to answer specific questions. The politician might not be willing to answer questions from several schools (depending on your actual relationship with the politician of course), so if you do intend to apply to several different schools, keep this in mind in order to choose his letter of recommendation for the school where you think it will do most good.
Good luck!