GRAND RAPIDS -- Republican presidential candidate Mitt Romney returned to his home state of Michigan Wednesday night, taking on President Barack Obama and organized labor.

The former Massachusetts governor spent much of his 20-minute speech in Grand Rapids going after what he called Obama's "crony capitalism." Romney said Obama has given huge financial favors to green energy industries and unions that contributed to his 2008 presidential campaign.

"(Obama) got hundreds of millions from labor bosses for his campaign, and so he's paying them back in every way he knows how," Romney said. "One way, of course, was giving General Motors and Chrysler to the UAW.

"I've taken on union bosses before, and I'm happy to take them on again," Romney said. "I sure won't give in to (the) UAW."

Romney, who spoke at an office furniture maker warehouse in Grand Rapids, has come under fire in Michigan for his opposition to the auto bailouts of 2009. Romney addressed his critics in his speech.

"I care very deeply about the auto industry," Romney said. "I want to make sure we have good jobs. Not just for a few weeks but for many, many years. I want the industry to come back in a big way."

Romney pledged to stand up for workers by fighting for right-to-work laws, which would give employees the option of whether or not to join a union instead of being required to join one.

"I'll fight for right-to-work laws, and I'm going to make sure we don't force unions on people," Romney said.

He took shots at Obama's record on energy, claiming he has favored companies that supported him and his fellow Democrats in 2008 over others. He also criticized the president's recent decision to strike down the proposed Keystone XL oil pipeline from Canada through the United States and pledged to approve it the day he takes office, should he win.

Romney, the son of former Michigan Governor George Romney, recalled a visit to Mount Pleasant for an Independence Day event with his family. His father stepped to the microphone and told the crowd how happy he was to be in Mount Clemens.

"My mother tried to help and say, 'George, it's Pleasant, it's Pleasant.' He said, 'Sure it's pleasant here in Mount Clemens,'" Romney said, drawing laughter from the crowd.

Byron Center native John Carlson attended the rally and said the biggest issues for him heading into 2012 are the debt and unseating Obama.

"He's the best liar I've ever seen," Carlson said. "And all politicians are liars."

James Broskey, an unemployed Grand Rapids resident who supported Obama in 2008, said unemployment and the economy are the issues on his mind this election season. He attended the rally to try to gain a better understanding of all the candidates and come to a decision afterward.

"I'm starting off with a clean slate this election season," Broskey said.

For Romney, the speech was designed to draw a contrast between himself and Obama and to give him a boost in the polls. Recent polls have him falling behind the president in a hypothetical matchup in November and against former Pennsylvania Sen. Rick Santorum in the Michigan Republican primary.

A recent Mitchell/Rosetta Stone poll showed Santorum ahead of Romney in Michigan by nine points. Likewise, Romney has gone from a two-point lead over Obama at the beginning of the year to a six-point deficit, according to a recent CBS/New York Times poll.