Perhaps the politician is a nut case himself, it has been known. Politicians also have their own agenda, or they are pushing the agenda of whatever party, or interest group, they belong to. IMO it is also strange that this seems to be the only mention of chemtrails by a politician, and this is being used to state a case for chemtrails existing. All this shows to me, (this is just my opinion), is that this particular politician believes that chemtrails exist.
He could very well be correct in his belief, but as far as being credible, that is something I think needs more investigation. This guy is a politician after all, and in my experience, politicians are not the most credible sources for evidence.