Robertson, a 45-year-old police officer, is voting for Barack Obama again tomorrow. And for him, it's clear why the president has faced such fervent hostility from opponents and detractors during his four years in office.
"To be honest, it's racism; it's the colour of his skin," Robertson told CBCNews.ca as he walked to Trinity UCC, a landmark of African-American faith and culture in Chicago, and where the Obamas were married 20 years ago by the sometimes controversial, now-retired Rev. Jeremiah Wright. "If he wasn’t black, Obama wouldn't be going through all of this."
That's one view, of course, and not something you hear from the top of either of the main campaigns. But as an undercurrent in an unexpectedly tight election – one fuelled by growing concerns about voter suppression tactics aimed at obvious minorities – it may yet be something to be reckoned with.
Four years ago, Chicago soared, and so did most of the world along with it. More than 200,000 people swarmed Grant Park to watch Obama make history with his election night victory speech.
"Between [NBA star] Derrick Rose and Barack Obama, we felt like Chicago's been put on the map," said South Side resident and first-time voter John Moran, who was 14 when Obama won in 2008. "As a city, we’re back and we're not just overlooked any more."
Four years later, with the economy still struggling and Obama locked in a tight and often bitter race for re-election, polls show an overwhelming majority of African-Americans still stand behind the president. But some are clearly wondering where the rest of the crowd went after that night at Grant Park.
Heading into the final day of campaigning, the president is leading in polls in several key swing states, and there are many pundits and pollsters who say he has more paths to an Electoral College win than Republican Mitt Romney does. It has probably also helped that the president won widespread praise for leading the federal response to Hurricane Sandy, including from New Jersey Gov. Chris Christie, a key Romney supporter.
Race played no part in that, and Obama’s opponents have bristled at any suggestion that his colour is a factor in the tight contest. They insist Americans have proven that they are above such prejudice by electing him in the first place, and shouldn’t feel bad about voting him out for not doing a good enough job of fixing the economy.
Still, Obama supporters point to examples of what they view as racially-tinged hostility toward the president from prominent Republican voices – from Sarah Palin’s “shucking and jiving” jab a few weeks ago to Rush Limbaugh's almost daily diatribes and most recently, a suggestion by John Sununu, one of Romney’s top supporters, that former Republican secretary of state Colin Powell only endorsed Obama, again, because the two men are black.
In the heat of the campaign, some conservatives have said they suspect liberals would blame an Obama defeat on racism no matter what happens. But how deep that blame might go is still an open question.
"Race is something that is uncomfortably and inaccurately dealt with in America," says Clarence B. Jones, a lawyer, professor and former adviser to the slain Dr. Martin Luther King, Jr. in the 1960s.
In an interview with CBCNews.ca, Jones said African-Americans will accept a Romney win – provided it is seen as being on the level.
"They’ll say, 'OK, we lost and I'm disappointed, but we'll try again next time,'" says Jones, who is currently teaching a course at the University of San Francisco on the history of race relations from slavery to Obama's election.
However, Jones added that he and other in the black community are concerned about the voter identification laws that were brought in by Republican-dominated state legislatures over the past two years, as well as by "rumblings" of attempts to spread confusion about polling hours and poll locations in districts with significant African-American or Latino populations.
"You don’t want 12 per cent of the population believing that the principal reason Obama lost is that he was black," he said. "That would be extremely damaging to the country and will feed a sense of cynicism that will be very hard to overcome."
Critics have condemned the voter ID laws as voter-suppression tactics targeting mostly poor or minority voters who are more likely to vote Democrat. In several states these laws have been held up in the courts after challenges from the Justice Department and voters' groups, and won't be in place for election day.
If Obama were to lose on Tuesday, anger within the black community could potentially boil over into a greater crisis than the intense Bush-Gore election result battle in Florida in 2000 – but only if "clear, convincing, perceptible evidence" emerges that the vote was somehow influenced by racially-motivated or underhanded conspiracies, Jones said.
Moran, now 18 and a freshman at Calumet College of St. Joseph in Indiana, says he expects some bitterness in Chicago if Obama loses, but he doesn't expect any huge protests if Romney wins.
"Some of the views he has, I just don't agree with as a middle-class African-American," he said as he and friend Juwan Johnson, 15, walk to a nearby McDonald's.
"It will be hard for us. But in terms of riots and that stuff, I don't think it's going to be that crazy."
As David Robertson neared his South Side church, he paused when asked about the possibility of a Romney presidency. "We’re the 47 per cent he was talking about," Robertson said, referring to Romney's now-infamous recorded comments at a private fundraiser that dominated the campaign ahead of the debates.
"I think we'll be in trouble, but black people have always got through trials and tribulations," he said. "We’ll just have to keep going."
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