MADISON, Wis. -

Protesters hissed and chanted "shame" at Gov. Scott Walker after he read a proclamation at the state's official Martin Luther King Jr. Day holiday ceremony in the Capitol rotunda.

Walker spoke briefly at the event Monday afternoon that attracted hundreds of people and featured a gospel choir from Chicago, a youth choir from Madison and a keynote speech from University of Maryland law professor Sherrilyn Ifill.

She elicited loud applause during her comments when she said that King would not have approved of laws requiring voters to present photo identification at the polls. Walker signed a photo ID law last year.

Ifill also drew applause when she said King would have stood up for worker rights.

Walker has been targeted for recall after he took on public sector union rights.

The jeers lasted seconds, as the ceremony focused on King's life instead of current politics. A diverse audience gathered to listen to songs and speeches that honored King.

The ceremony also honored three Wisconsinites who made a significant difference in their communities. Former Madison Fire Chief Debra Amesqua was among those honored.

Before she rallied the crowd over workers' rights and voter identification, Ifill talked about the country's need to push for more progress.

"It's so easy, especially these days, to become cynical," Ifill said. "To believe we've gone as far as we can go, or even as some people will say, that we're going backward."

Walker only spoke to read the state's official proclamation, although he stayed throughout the ceremony.

The state's ceremony at the Capitol was one of several ceremonies planned to mark the day across the state.