Sen. Barack Obama (D-Ill.) believes that investigations of his questionable relationships — with dubious characters like Jeremiah Wright, Tony Rezko and William Ayers — is nearing an end as the public tires of persistent inquiries into the past of its newfound prince and his one-time courtiers. But Obama may face a new and more serious scrutiny, one that doesn’t look back at past outward associations, but that instead looks inward. The mind of Barack Obama is about to get a once-over.