Here's the earmark problem in a nutshell. 

The Bush administration apparently adhs ecidied to refuse to spend about $900 million that had been slated for an extension of the subway system in the Washington area to Dulles airport.  The project had been in the works for more than a decade, had been considered crucial for an area with extreme transportation problems, and had substantial support from Republicans as well as Democrats. But just as the project was about to move forward, and very unexpectedly the administration pulled the plug on the federal funds. Although there is some talk about private money being available, the current prevailing opinion is that this could kill the rail extension.

One of my most fiscally conservative colleagues was outraged at this.  He sees this not as a special interest project for a particularly geographic area, but rather as a major need in the nation's Capital.  He raged when I insisted it was an earmark inserted by local leaders and said the spending was absolutely necessary.  He refused to accept that this project for northern Virgina was no different from a highway somewhere else in the U.S.

My guess is that most people who live Somewhere Else USA agree with me about the $900 million but agree with my colleague that their highway is not an earmark.