Sample was hospitalized and is in stable condition with head injuries, which are not considered life threatening. The attack occurred during a march by the "Poor People's Economic Human Rights Campaign."

The group of several thousand did not have a permit, but reportedly negotiated with police to let them march to the Garden. Law enforcement sources said they feared further incidents might mar Tuesday's proceedings, beginning with an expected protest outside a Texas delegation breakfast for the Halliburton company.

Protesters have dubbed Tuesday "Direct Action Day," with disruptions and civil disobedience planned at different sites throughout New York City. Monday night's violence was in marked contrast to Sunday's march on the Garden by the radical umbrella group United for Peace and Justice, which went off largely without incident. Sunday night, however, a female GOP delegate attending a Broadway show was jostled by demonstrators, who pelted her with vulgarities.

Editor's note: