1. kenyan birth certificate - Very possibly, but I'm not sure it would have the impact Trump describes;
2. Proof of fraudulent use of social security number;
3. Proof of fake draft registration
4. Proof of fraud, and / or admission of non-citizenship by receiving aid as a foreign student;
5. Hussein's transcripts;
6. Proof the Saudis got him into Harvard Law School with a huge donation, making him beholden;
7. Proof of his membership in the communist party;
8. Proof that he is a muslim;
9. Proof that his trip to Pakistan was sponsored by russia, china, muzzies, etc. for him to attend terrorist training camp;
10. Proof that his rumored gay affairs are true.
Add to the list or take your pick.