DETROIT (AP) - An aggressive Rick Santorum went after Mitt Romney on multiple fronts Thursday, challenging the Republican front-runner's economic policies, values and consistency in the city of his birth.
Santorum criticized his rival's record on federal bailouts in particular, although both men opposed the government's decision to rescue the auto industry.
"Gov. Romney supported the bailout of Wall Street and decided not to support the bailout of Detroit. My feeling was that the government should not be involved in bailouts period," Santorum said in an address to the Detroit Economic Club, just 23 miles from where Romney went to high school. "I think that's a much more consistent position."
Santorum spoke as Romney campaigned elsewhere in Michigan, ignoring Santorum and two other rivals for the GOP presidential nomination altogether while focusing his criticism on President Barack Obama.
Santorum, who has surged in state and national polls, is showing greater confidence in what should be safe territory for the longtime GOP front-runner. Romney not only grew up in Michigan, he is the son of a former governor. His family members also have been deeply involved in the state's politics for decades.
Despite those inherent advantages, Santorum vowed earlier in the week to "plant our flag" in Michigan, where the presidential primary is Feb. 28. He began to make good on that promise Thursday.
Known for staunch socially conservative views, Santorum outlined an economic policy with a heavy emphasis on family values. He supports additional tax breaks to encourage charitable donations to churches, for example.
"We certainly won't be able to have limited government, lower taxes, if the family continues to disintegrate," he said.
Santorum also linked Obama and Romney, suggesting neither wants to lead the entire country as he would.
"We have a president who says he supports occupiers who divide America between 99 and 1. We have another candidate in this race who suggested that he didn't care about the very poor," Santorum said of Romney. "How about a candidate who cares about 100 percent?"
And while he said he supports economic opportunity for all, Santorum said income inequality is good.
"Why? Because people rise to different levels of success based on what they contribute to society and to the marketplace and that's as it should be," he said.
Santorum also reiterated his "Made in America" plan to eliminate a 35 percent corporate income tax on manufacturing to help rebuild the industry. He also wants to increase a tax credit for research and development, from 14 percent to 20 percent, to help create high-tech jobs.
Santorum spoke hours after he released tax returns showing his average income exceeded $990,000 in recent years. He paid a considerably higher tax rate than Romney, whose income largely comes from interest on investments.
"Look, I do my own taxes. Heck, Romney paid half the tax rate I did, so obviously he doesn't do his own taxes," Santorum said. "Maybe I should hire an accountant in the future."
Santorum sought earlier this week to minimize expectations for winning Michigan, but he hopes to score a victory that could be a huge embarrassment for Romney. The former Massachusetts governor has struggled to persuade his party's most conservative segments to embrace him.
Despite the challenge from Santorum, Romney campaigned Thursday using a formula that served him well in Iowa and Florida: staying positive while using TV attack ads to undermine his chief opponent.
Romney did not mention Santorum - or Newt Gingrich or Ron Paul - in two campaign stops in Michigan. At a business round-table at a steel galvanizing plant in Monroe and in an address to a Chamber of Commerce in suburban Detroit, Romney focused almost entirely on business and the economy. He repeated his calls for lower corporate tax rates and less regulation, and gave Obama no credit for the slightly improving economic picture.
Obama "has taken actions which have made it harder for our economy to recover," Romney told the chamber gathering.
Meanwhile, Romney and his allies are vastly outspending Santorum on Michigan's airwaves, including with ads attacking the former Pennsylvania senator for voting to increase the federal debt ceiling. Local Romney supporters also held a conference before Santorum's speech to criticize his support in Congress for pork-barrel spending.
The underfunded Santorum defended himself, saying during his speech that he was "the most conservative senator by far based on the state I represented and the spending record I had."
Though unable to match Romney on the air in Michigan, Santorum is airing one ad featuring a gun-toting Romney impersonator shooting mud at a cardboard cutout of Santorum. An announcer says Romney's "negative attack machine" is on "full throttle" and accuses Romney and groups that support him of "brutally attacking fellow Republicans."
Charles Babington in Farmington Hills, Mich., contributed to this report.