Barb may have more to say on this, but the New York Times headline here makes a clear, simple point:

The myth of "widespread voter fraud" is simply a tool to disenfranchise voters. The Bush administration and others who have perpetuated and overhyped the notion of a voter "fraud" conspiracy are, on this issue, simply frauds. And now they find themselves embroiled in a scandal in part because they pushed U.S. Attorneys to further this sham.