Hundreds of thousands of protesters took to the streets Sunday in the largest demonstration ever at a political convention. Organizers with United For Peace and Justice estimated more than a half million protesters marched past Madison Square Garden where the Republican National Convention opens today.

In New York, major protests against President Bush began on Friday when 5,000 bikers took part in a Critical Mass bike ride. Some 15,000 marched on Saturday in one of the city’s largest women’s marches in history. Today two more large demonstrations are scheduled to mark the start of the convention.

Over the weekend police arrested some 400 protesters. Four activists who participated in a banner drop on Thursday at the Grand Plaza hotel now have 25 years in prison. They were each charged with assault because a police officer was injured while responding to the incident.

Meanwhile Vice President Dick Cheney arrived in New York Sunday and spoke at Ellis Island in an event closed off to the public. He spoke with the background of the lower Manhattan skyline as a backdrop.

We’ll have much more on the protests throughout the show.