Nearly 1,000 labor union members and their supporters rallied in the state Capitol Monday, voicing their opposition to proposed legislation that would weaken collective bargaining rights for Iowa’s public employees. The group then filled the Iowa House chambers for a public hearing on the bill, with opponents vastly outnumbering the handful of supporters who spoke up for the legislation. “This is about the right for workers to be able to bargain in the workplace,” said Mark Cooper, president of South Central Iowa Federation of Labor.