The War Center
It's noteworthy how the McCain-Lieberman alliance is portrayed in the press as a kind of "centrist" independent fusion movement when the main thing that brings them together is their shared ardor for an unpopular war in Iraq. They both clearly see their views on Iraq and related matters as their most important priorities in public life, and the views they share on this subject are well to the right of the median Americans. And yet, they're in the center. One assumes that a Dennis Kucinich / Ron Paul lovefest on national security issues would, by contrast, be talking about as an example of "extreme" views being similar to one another.
The dynamic here clearly has less to do with public opinion than it does with establishmentarian ideas about what is and is not extreme. Washington, DC (or, even more so, the suburbs in Virginia where the power-brokers live) is a kind of place where heavy military equipment is advertised on the subway and defense contractors are a major engine of employment and economic growth. Which isn't to say that there's a direct, connect-the-dots relationship between the C27-J Spartan ad campaign and media portrayals of the Lieberman-McCain worldview, but I think it's important to understand that a kind of casual militarism permeates the atmosphere and anything that serves the cause of ever-growing procurement acquires a veneer of respectability.