The limo driver is his only evidence, who will apparently turn up as a witness once all newspapers start publishing the story. The sad part about "The Right Perspective" is that the hosts of the show were sucking up to this guy. Looked like the interviewers very of pretty low intelligence not asking really sharp questions and taking whatever Sinclair said at face value.

To one question he says the limo driver has known Obama for a very long time. Then when asked if Obama will track the limo driver down, this guy says, no. Apparently Obama uses several limo drivers.

Another proof he has is that he told his friends the next day that "he got lucky". Did he tell his friends that it was with Obama? And who are his friends?

Apparently, he says he has been trying to get this story out for a long time but the press refuses to publish it. The Right Perspective were sucking up to him saying how they are the pioneers. May be it hasn’t occurred to the Right Perspective journalists that others are smarter and have more judgement.

Sinclair has also admitted to mental illness during childhoold and some issues with his mental health condition during adulthood.

My questions are:
(a) Why is he staying now in a low cost assisted facility if he pulled in millions ten years ago?
(b) If he bought/sold coke amounting to so much, is he confessing to some serious drug trafficking? Won’t the DEA be after him?
(c) Why did he stay at some low end motel in Chicago when he could afford so much more?
(d) The guy has never seen Obama before. What makes him think that someone he met is Obama? I myself couldn’t recognize him from his photograph.
(e) Why is he trying to get this out now (knowing that consensual sex is not a crime) and that dealing in high volume of drugs will get him into long prison sentence with DEA?
(f) Even if the limo guy is an evidence, what makes us believe that the guy was not bought off by whoever is paying for this?

Regarding lie detector test, they are not reliable. Read wikipedia article on polygraph tests for more detail. Chances of a truth being flagged as falsehood is not much higher than vice versa.

“who at the time was a state representative for the state of Illinois.”

He was a state senator, not a representative.

He also says his hotel was in Gurnee, Illinois. Expedia shows 7 hotels in Gurnee, Illinois, the most prestigious of which is the Comfort Suites. Which, you know, who doesn’t roll up to the Comfort Suites in a limo?

http://www.nstc.navy.mil/rtcgl/family/upcominggrad.html

So your entire argument is moot.