You may recall a recent example--in 2005--on the second anniversary of the start of the Iraq War. Thousands had hoped to make a statement marching south on Michigan Avenue in protest of the war. Instead, they were herded by Chicago police (some in riot gear and on horseback) down Clark Street, instead. Many in the crowd saw the less prominent thoroughfare as a way to diminish the impact and message of the demonstrators.
So what's this? Chicago Mayor Richard Daley lamenting --in passionate terms--that there aren't more anti-war protesters in the streets of Chicago?