Why does the media care more about Joe Wurzelbacher's record than Barack Obama's record?

Joe the plumber was on the Mike Huckabee show last night. I was unable to watch it but the Toledo Blade has some coverage. I have been amazed at how the mainstream media can apply journalism to Joe’s past but for some reason we hear very little about Obama’s past. Understandably, the scrutiny is intimidating to Joe W.

Mr. Huckabee said that Mr. Wurzelbacher only asked a question when Mr. Obama happened to stop by his current neighborhood a week ago. Mr. Huckabee asked how Mr. Wurzelbacher felt about the scrutiny he’d received.
“It actually upsets me,” Mr. Wurzelbacher said. “I am a plumber, and just a plumber, and here Barack Obama or John McCain, I mean these guys are going to deal with some serious issues coming up shortly. The media’s worried about whether I paid my taxes, they’re worried about any number of silly things that have nothing to do with America. They really don’t. I asked a question. When you can’t ask a question to your leaders anymore, that gets scary. That bothers me.”

The moral is, if Barack Obama comes to your door, don’t answer.
Most of what I can find about Obama’s record on housing is on blogs or primary sources. Other than the Boston Globe article, where is the investigative reporting of Obama’s record in Chicago?