The terms are a bit messed up, but the closest thing these are to a US organization is a presidential campaign policy working group. [1] These are the guys who basically act as advisors to the government's top politicians on issues that relate to technology.

Edit: They don't only manage the online presence of the political party. They are more detailed, coming up with policies and papers (presumably - none of these ever show up in public, oddly) [2]

[1] As an example, here's Obama's - http://change.gov/learn/policy_working_groups

[2] The head of the IT cell's LI profile - https://www.linkedin.com/in/argupta26