Why `python-httplib2` package is not available for RHEL6?

Issue

• Unable to install python-httplib2 on server running Red Hat Enterprise Linux 6.x.

  # yum install python-httplib2
  Loaded plugins: product-id, refresh-packagekit, rhnplugin, security, subscription-manager
  [...]
  Setting up Install Process
  No package python-httplib2 available.
  Error: Nothing to do