This is speculation, but Alex Jones has predicted things before...such as 9/11, so I take his prediction now (backed up by an excellent article on Infowars) seriously. The idea is that the neoconservatives who are dying to start a war with Iran might organize an assassination attempt on Obama to somehow be blamed on the 9/11 Truth movement who the neocons continually describe as a danger akin to terrorism. (One good example of this is this article where the 9/11 Truth movement is compared to the Fort Hood shooter.)
According to Prison Planet, the motive for the assassination attempt will be to blackmail Obama into starting a war with Iran. That's the basic idea. Check out their article for more details.