anchor: As we have pointed out, [i]t does not follow . . . that viewpoint-based restrictions are proper when the [government] does not itself speak or subsidize transmittal of a message it favors but instead expends funds to encourage a diversity of views from private speakers.
positive: Restrictions are appropriate when the government does not speak of the transmittal of a message it favors.
negative: Restrictions are inappropriate in any situation regarding transmittal of a message the government favors.