Well I have this throw away e-mail address that I get a lot of "interesting" spam sent to me. I have been finding some rather unusual e-mail from Barrack, Michelle, and Joe too. When you look at the header information, it is being sent from the IP 18.104.22.168 which belongs to EHLO mta-inap4.bluestatedigital.com. It appears that the Obama campaign doesn't mind buying e-mail lists so they can spam to millions. The people who maintain these large e-mail lists are actively participating in not so nice ways of collecting these e-mail addresses.
I'm not an Obama fan. Not really that much of a McCain fan either. I do notice that I haven't got these types of e-mails from the RNC. And I find at the bottom of the e-mail, an unsubscribe link. I have always advised people to NEVER click on links in spam e-mails because you don't know what the person responsible will do with this information. Those with not so good intentions use the unsubscribe link to verify that they have a valid e-mail address and that address will be "verified" in a way that these people who market these list can sell for more.
Delete all spam e-mails that you get. Never, never, never click on any links or attachments from unsolicited e-mails.