Supposedly from "Obama Home Help" - whatever that means. Could be someone phishing scam to get credit card info for a "donation" that probably goes in their pocket. I doubt that this has anything to do with Obama, the Democratic Party or any campaign fund raising organization.
People - if you want to donate to ANY candidate go to their website and do it there. You'll know it went to the correct place. Since anyone with the proper equipment and know how can make their caller ID say anything they want - don't believe it unless you're sure of the number.