Separate Content Based on Groups

Hi,

I know that Drupal is the grand poobah of community-based sites, but not sure even it can tackle this situation?

1) User registers. Submits Photo (important) and info.

2) Administer reviews registration info and places user into one of three groups.

3) Each group, following log-in, is presented with its own information, specific to that group.

It's highly important that each group can not view the other groups' content, or even know that the other group exists.

To be more specific, it would almost be like having 3 completely separate sites - with all information presented specific to each user group.

I guess the best analogy would be -

Imagine a political site that wanted to serve Republicans, Democrats, and Independents. Once someone registered, was assigned to a group, and logged in, the site would automatically behave as either pro-Dems, pro-Rebs, or pro-Independent.

Thanks for any info.