Protesters heckle Tammy Baldwin on Syria by singing “Which side are you on?” at the Fighting Bob Fest.

Internal divisions on the left.

U.S. Sen. Tammy Baldwin, D-Wis., ... who opposed strikes in Kosovo, Iraq and Libya -- said she would continue asking President Barack Obama’s administration “tough questions” to further the debate. 

She wouldn't say how she would vote.

ADDED: It looked like this: