Oh, yeah. I always take sleep medications then go for a drive. Doesn't everyone?
It makes sense to me... After all, he took the sleep medication, and only then did he realize that he was late for a vote, so he hopped in his car and drove in the general direction of the Capitol, in search of police officers who could escort him through the 3 AM traffic to get to the vote more quickly. And, and, and, get this, he found them, exactly like he planned. And his lights were off because... because... because he was saving energy due to the Bush oil crisis, yeah, that's why his lights were off...
Don't be so hasty. I've taken Ambien for several years (under MD's care, of course) and know what can happen when a person is disoriented from it. Talk about sleepwalking! There are documented cases of people doing all kinds of complex things--cooking meals, showering, painting, writing, having sex, and yes driving--after the drug takes effect, without any memory whatsoever the next day. I know this is true because I've experienced some of it myself. I've never, ever attempted to drive my car (I'd be off it immediately if I had!) but there are times when I've prepared food and eaten it, did laundry or other housework, or had long conversations with my husband, and then had total amnesia of the incident/s afterwards. Do a Web search and you'll find all kinds of anecdotal data. Many people have experienced similar situations.
Ambien is one of the most widely prescribed medicines in America, and some people are taking it like candy without considering its possible serious side effects. Combined with another drug, it could very well have contributed to such an incident. (Okay, now I can't believe I'm in the almost intolerable position of offering a possible defense for a Kennedy, but there it is!)
You must also slip a phenergan suppository up your arse. They do make you very sleepy. I slip in two or three and then go for a drive.