Can't help but mention the sites.usa.gov project being run by the US General Services Administration, offering 'a shared service to help agencies focus on creating great content rather than on building systems to deliver that content'. No charge initially, but looks likely in due course. And yes, of course it's running on WordPress.
By providing agencies with a content management tool that is up-to-date, supports open content, is secure, compliant and hosted, we can help government agencies meet the goals of the Digital Strategy: to enable the American people to access high-quality digital government information and services anywhere, anytime, on any device. You concentrate on carrying-out your mission and engaging with citizens, we do the infrastructure lift.
Can't argue with that. Nor would you expect me to, having advocated precisely such an approach for at least four years.