demonstrations are a form of political activity in the united states, and one popular place for them is the sidewalk in front of the white house in washington d.c. people demonstrate there in order to call the president's attention to an issue, and also to gain national publicity. The government cannot prohibit these demonstrations because the right of free speech is guaranteed in the u.s. constiturion. However, there are laws which regulate demonstration on the white house sidewalk, and the police enforce the regulations.