DETROIT -- With a new poll showing a virtual dead heat in Michigan's Feb. 28 presidential primary, the leading Republican candidates veered Thursday from defensiveness to discomfort.
Rick Santorum was forced to rebut an attack ad by a pro-Mitt Romney super PAC that labels him a "big spender" for his votes in Congress.
Santorum responded that the conservative National Taxpayers Union had rated him the fifth most conservative senator.
"I ... stood for limited government," Santorum said.
Romney, meanwhile, was in the position of defending his opposition to the bailout of GM on the same day the auto company reported record profits of $7.6 billion.
Romney said Thursday that he is "delighted" that the industry is profitable.
Meanwhile, Santorum's newly released federal tax returns show he grew wealthy working as a consultant and media commentator after leaving the Senate in 2006.
His annual adjusted gross income surged from nearly $660,000 in 2007 to $1.1 million in 2009.
The leading GOP contenders campaigned a few miles apart in the Detroit metropolitan area, a central battleground in the high-stakes primary in Romney's native state. A statewide poll published Thursday showed Santorum leading 34 percent to 30.4 percent, within the survey's margin of error.