The president-elect of the US, Barack Obama, has released the office of the president-elect webpage change.gov under a Creative Commons 3.0 Attribution License. Meaning that you are free to copy, distribute and remix the work, as long as you mention the source.
It is of course so, as IPKat writes, that politicians have an inherent interest to have their views spread to as large audience as possible. But, one really important thing is, to keep some level of control over the message you communicate. I do not think that this license issue of the website content will affect his presidency in any major way. It can and could very well be so that the collaborative nature of this has made him more popular.
There is however an interesting difference in the copyright statements on the official campaign site barackobama.com since it there is not explicit if you are allowed to remix the content. That you can print and distribute is ok, as long as you mention the source.
As I see it, there can both be good and less good aspects of giving away the possibility to use elements from websites and campaigns as the ones mentioned. Since all communication interfaces are part of the overall brand I believe that there needs to be a consistency when it comes to the message communicated. But in the age of access where the masses can, and probably will, do what they like anyway, it might be hard to control all uses.
So, it might instead be more beneficial to limit the access to some parts and use openness in other areas. Just as Mr Obama has done.