Doing the work on people we back and people our companies hire is absolutely critical to our job. We have networks that usually provide a bunch of great reference opportunities. And we use databases to do additional work. That doesn't mean we don't make mistakes, but we get it right more often by doing the work.
It looks like The White House could take a lesson in vetting candidates, if the job they did on Kerik is typical of the work they do.
This White House may have excellent political instincts, but they sure do screw up the execution.