And now, we turn to that showdown raging in the heartland of the united states. Per hatches no place in america more closely associated with unions than the state of michigan. And today, thousands of union workers descended on the capital to protest a new law they believe could be an ominous signal for unions and worker paychecks everywhere. Here's abc's alex perez. Reporter: The anger boiling over. Officers turning to pepper spray to control the crowd at least 10,000 deep. But it wasn't enough. Michigan republican lawmakers approving landmark legislation, lifting the requirement that workers in unionized workplaces pay union dues. An army of officers have been guarding the governor's office all day. Some of these demonstrators have been here since 5:00 this morning. The republican governor has signed the law. With a stroke of a pen, take our rights away. It's offensive. Reporter: Supporters call it right to work, but unions say it's nothing less than an effort to cut their bargaining power. Less dues means less influence. The afl-cio says the average worker earns ,500 less than work workers in states without that law. They have everything to do with politics. Reporter: But supporters say the law encouraging business. Chris owns a construction company and predicts the bill will allow his company to hire more workers. This will attract more businesses to michigan. Those businesses will need space and we're here to build it for them. Reporter: What's remarkable about what happened today is that it happened in michigan, the heart of union country. Home of the united auto workers. Now michigan will become the 24th right to work state. Alex perez, abc news, lansing, michigan.