ST. PETERS, MO. — Some white union members in the suburbs northwest of St. Louis are blunt about their racism when Gary Booth knocks on their doors.
"I am not voting for a black man," they tell Booth, who leads organized labor's Democratic campaign effort in nearly all-white St. Charles County.
Others are indirect but make clear that their unease with Barack Obama's race will influence their vote on Tuesday. "It's a difficult thing to try to break down those barriers," Booth said.
Whether Obama or Republican rival John McCain carries Missouri depends in no small part on the nearly 250,000 voters of St. Charles County, a fast-growing working-class area. It would be tough for any Democrat to win in this culturally conservative county, where many voters oppose abortion rights and gay marriage. However, the troubled economy and Obama's huge campaign operation have put the entire state in play.
The nominee is making two trips to Missouri in the campaign's final week. He has 44 offices in the state, which President Bush won handily in 2004, compared with McCain's 16. As for unpaid volunteers in Missouri, Obama has thousands.
Steven S. Smith, a professor of political science at Washington University in St. Louis, said Obama's campaign was the most elaborate any presidential candidate had ever mounted in Missouri. "The sheer number of campaign volunteers going door to door -- get-out-the-vote, voter-registration efforts -- has been beyond belief," he said.
Obama also is spending three times as much as McCain on television ads in the state.
Missouri's economic distress also has enhanced Obama's prospects. In St. Charles, a county of 344,000 near the convergence of the Missouri and Mississippi rivers, rising home foreclosures attest to the tough times. So do the 10,000 new empty lots on the county's exurban frontier: Developers leveled them to build houses but cast aside construction plans in the absence of buyers.
Still, race remains a potent force in the White House contest here, even as Obama's top advisors argue the contrary.
"The truly undecided are not undecided because of race," campaign manager David Plouffe said. "They're undecided because they haven't decided who's best on taxes, healthcare and other issues."
But the effect of race in Missouri is apparent to Tommy Roberts, the Democratic chairman of St. Charles County. Leaning on a desk in the bustling Obama office here, Roberts recently recalled the racist graffiti scrawled on cars out in the parking lot one night.
"If Barack Obama was a white guy, he'd win St. Charles County," said Roberts, adding that he would be "tickled pink" if the Illinois senator gets more than 46%.
"People flocked to St. Charles County to get away from the black people in North St. Louis," he said.
Alluding to white families who fled St. Louis for nearby suburbs, only to migrate a generation later to St. Charles County as blacks moved farther out of the city, he added: "They're scared to death this North County issue is going to happen all over again."
At a card table, Obama volunteer Kayla Kremer, 63, was placing phone calls to voters. Her home is in Dardenne Prairie, a community 20 miles from St. Louis that is more than 95% white. When she calls upon neighbors to support Obama, Kremer said, some "slam the door in my face." Others say, "Absolutely not."
"There is a lot of underlying racism," said Kremer, a pediatric nurse practitioner who has never before volunteered for a campaign. "I think if he loses this area, it's because of that."
But for many whites in St. Charles County, the dismal economy has trumped misgivings about race. On a recent trip to the Mid Rivers Mall in St. Peters, Pat Nagle, 69, said Obama might be a "wild card" but seemed better suited than McCain to lead an economic recovery. "My husband was going to retire at the end of the year," Nagle said, explaining that she and her husband have lost a big chunk of their savings in the stock market. "Now he's thinking maybe he won't retire at the end of the year."
McCain and his running mate, Sarah Palin, have both campaigned in St. Charles County -- one of Missouri's biggest troves of Republican voters. Many -- like Delano Sylvester, 75, of Lake St. Louis -- would rarely, if ever, vote for a Democrat. Sylvester, a retired Air Force officer who also was at Mid Rivers Mall, said he saw Obama as a liberal who was unqualified for the presidency.
"I wouldn't consider voting for a socialist," he said.
Republican leaders say Obama will be hard-pressed to break through such resistance, no matter how sprawling his organization.
"It's sort of like trying to sell meat to a vegetarian," said Jared Craighead, executive director of the state Republican Party. "It doesn't matter how in-your-face you are."