"I've got a lot of friends ... (who) are like, 'Oh, no'" when it comes to voting for a black presidential candidate, said John Martin, a 42-year-old Democrat from Macomb County's Harrison Township who backs Obama. "They're all working people, all in unions, plumbers and stuff like that. ... A few of them have said they're not even going to vote."
That attitude could cost Obama in a state that has voted Democratic since 1988, but in ever-narrower percentages. Democrat Al Gore defeated George W. Bush by 5 percentage points in 2000, but Democrat John Kerry won against Bush by just 3 percentage points in 2004.
Race is always an uneasy subtext in Michigan, which suffered through 1967 race riots in Detroit and still has a mixed relationship with its often-struggling largest city.
It's an especially potent issue in southeast Michigan, where mostly black Detroit is surrounded by mostly white suburbs in western Wayne, Macomb and Oakland counties. The metropolitan area, among the nation's most segregated, just went through a steamy text-messaging scandal that ended in Detroit Mayor Kwame Kilpatrick resigning in a plea deal in which he pleaded guilty to two obstruction of justice charges and no contest to assault.
Although Detroit residents - more than 80 percent of them are black - are expected to turn out in record numbers for Obama, the black mayor's troubles have created a cynicism among many suburban voters that could hurt Obama.
Freedom's Defense Fund, a Washington-based group that opposes Obama, is spending $25,000 to run an ad on cable news channels in Macomb County that shows Obama praising Kilpatrick last year before the mayor's legal troubles began.
"I think he is running on his judgment, and we think it's pretty poor in this instance," said the group's executive director, Todd Zirkle.
Democratic Gov. Jennifer Granholm, an Obama supporter, criticized the ad during an appearance this week on MSNBC.
"That clip was taken a year and a half ago, before any of this came up," she said. "The fact that it is being run in a predominantly white suburb tells you that there is an explicit effort to try to divide people by race."
But Republicans think tying Obama to the racially polarizing mayor might help McCain, particularly in Detroit's suburbs. A recent CNN/Time/Opinion Research Corp. poll showed McCain leading Obama by 14 percentage points among whites in Michigan. The Republican also had an 18-point lead in the Detroit suburbs, which split about evenly between Bush and Kerry in 2004.
Overall, the race is a dead heat in Michigan, the poll showed.
Obama is concentrating his frequent appearances in the state on the pocketbook issues that concern most Michigan residents: whether they'll still have a job or a home next year, and whether they can afford health care for their families, college educations for their children or gasoline for their cars. His running mate, Joe Biden, was planning two appearances in Michigan on Monday.
The state has shed more than 315,000 manufacturing jobs since mid-2000 and has the nation's highest unemployment rate and seventh-highest mortgage foreclosure rate.
But many Michigan voters still don't know much about Obama, who took his name off the state's Democratic primary ballot to avoid angering early voting states such as Iowa and New Hampshire.
The Illinois senator didn't campaign in Michigan until May, four months after Republican rival John McCain had engaged in a vigorous - although unsuccessful - GOP campaign against Michigan native Mitt Romney.
McCain's folksy style, his military record and his patriotism connect well with Michigan's blue-collar voters, one reason he was able to win the state's 2000 GOP primary over Bush with the help of Democrats and independents.
It's a record that could appeal strongly to voters north of Detroit in Macomb County, home to many of the "Reagan Democrats" - blue-collar, socially conservative voters who often are Catholic and of eastern European descent. Many are older residents who oppose abortion and support gun rights, even as they ardently defend their union rights.
That's a profile that lines up closely with Republican vice presidential candidate Sarah Palin, the Alaska governor who likes to hunt and whose union-member husband has worked in oil fields and raced snowmobiles, a popular pastime in Michigan.
Bernie Porn of the Lansing polling firm EPIC-MRA said conservative Democrats and swing voters can be won over by Obama but are skeptical that Obama feels their pain. Comparing polls from July and August, Porn said he saw slippage in Macomb County among Reagan Democrats, union members and Catholics.
There's also the issue of affirmative action. Two years ago, Michigan voters passed a ballot measure that banned using race or gender in university admissions or government hiring.
The measure got 58 percent of the vote statewide; it picked up 68 percent in Macomb County. The county went for Republican George H.W. Bush in 1992, for Democrat Bill Clinton in 1996, for Gore in 2000 and for George W. Bush in 2004.
Oakland County, which includes the struggling city of Pontiac as well as some of the nation's richest ZIP codes, voted for the first President Bush in 1992 and for Clinton, Gore and Kerry in subsequent elections.
That trend could continue this year, with Obama appealing favorably to the county's socially progressive Republicans, especially women unhappy with Palin's strong opposition to abortion.
A win in Macomb isn't necessary for Obama to win the state. But Detroit has lost about 71,000 eligible voters since 1992, according to state demographer Kenneth Darga. Even with higher turnout, Obama could see fewer votes from the city.