Republican White House hopeful Rick Santorum defended himself against attacks from Mitt Romney on Thursday as his hopes rose of dealing a heavy blow in Michigan to his main rival, who was the party front-runner before falling behind in national polls.
Santorum, a former Pennsylvania senator who has emerged as a major threat to Romney in the race for the 2012 Republican presidential nomination, used a speech in Detroit to push a blue-collar theme in the state where the struggling auto industry has helped push up unemployment.
"We have to be concerned about everybody, from the very rich to the very poor," he said.
Michigan and Arizona hold the next contests in the 2012 race on February 28 and could offer important momentum before the March 6 Super Tuesday jackpot when 10 states vote. Republicans are seeking a candidate to challenge Democratic President Barack Obama in the November 6 election.
Romney leads in Arizona, but he is running neck and neck with Santorum in Michigan, where Romney's opposition to the 2009 auto bailout is contributing to his risk of losing the state where he was born and where his father was a popular governor.
In a sign of the critical importance of Michigan, a pro-Santorum group flexed its muscle for the first time after weeks of inaction. The Red, White and Blue Fund bought nearly $663,500 worth of ads in Michigan, versus the $886,000 the pro-Romney group, Restore Our Future, reported spending on the spurt of anti-Santorum ads running through Monday.
Romney may get some help from Thursday's endorsement by Michigan's popular governor, Rick Snyder. "Mitt understands the challenges confronting Michigan as few Americans do," Snyder wrote in The Detroit News.
A series of opinion polls this week showed former underdog Santorum leading Romney both nationally and in Michigan.
Santorum rejected attacks from the Romney campaign that he was known in Washington as a big spender of taxpayer dollars, insisting he was a fiscal conservative while representing Pennsylvania.
The Romney campaign has used Santorum's support for millions of dollars in government spending projects, including a $400 million "bridge to nowhere" in Alaska, to try to undermine Santorum with conservatives worried about rising debt.
"I was the most conservative senator by far based on the state I represented and the spending record I had," said Santorum.
A day after releasing his tax returns, Santorum took a dig at Romney, a multimillionaire former private equity executive.
"I do my own taxes. Heck, Romney paid half the taxes I did. He doesn't do his own taxes. Maybe I should hire an accountant in the future," Santorum said.
Santorum, a strong social conservative, made his attacks at the Detroit Economic Club, the kind of pro-business audience more likely to be friendly to his rival.
But Romney has drawn fire in the state for his criticism of government bailouts of auto giants General Motors and Chrysler.
Romney said Chrysler and GM, which reported a profit of $7.6 billion in 2011, would be even stronger if the government had stayed out of the way. He said the companies eventually went through a "managed bankruptcy process" that allowed them to survive.
'I Love the Auto Industry'
"I love the auto industry. I want to see it thriving and growing. I'm glad it went through a managed bankruptcy process, which I recommended from the very beginning to shed unnecessary costs and get its footing again. I'm delighted it's profitable," Romney said in Farmington Hills, Michigan.
Santorum pronounced himself pure in opposing government bailouts of private industry, saying he had opposed not only the auto bailouts but the bank bailouts of 2008 and 2009, which Romney had backed.
Romney was quick to point out that Santorum said at the time
he did not think the bank bailouts were "an unreasonable decision."
Many of Romney's troubles stem from suspicion among conservatives he is not one of them. The topsy-turvy 2012 campaign has been marked by the rise and fall of a series of anti-Romney conservative alternatives including Michele Bachmann, Rick Perry, Herman Cain and Newt Gingrich.
Santorum is the most recent and his late emergence gives him a chance of knocking out Romney, who has run a front-runner-style campaign, focusing most of his attention on Obama.
Santorum took several shots at Romney, mainly over his vast wealth and his recent comment that he was not worried about the poorest Americans because a safety net exists for them, a statement Romney later retracted after a media hubbub.
Santorum noted he paid a higher tax rate than Romney, whose effective tax rate was 13.9 percent because his income is based on investments.
Santorum's tax documents showed he built a sizeable income that came partly from lucrative jobs through his Washington contacts. He paid an average of 27 percent in taxes over four years, owns a German-built Audi luxury car and in 2007 claimed a $4,000 deduction for clothing donated to charity.
Santorum has taken over the mantle of the conservative anti-Romney hopefuls from Gingrich. The former House of Representatives speaker's campaign suffered a blow on Thursday when a planned March 1 debate of Republican candidates in his home state of Georgia was canceled after Romney and Ron Paul dropped out, and Santorum's campaign expressed doubt he would attend.
(Additional reporting by Sam Youngman and Alina Selyukh)