Last September, when Barack Obama's approval ratings were in the low to mid-40s and a clear majority of Americans said he did not deserve a second term, veteran pollster Charlie Cook described his ideal Republican opponent as "odourless and colourless". With unemployment and the deficit so high and gridlock so stubborn, he explained, a challenger who did not repel independents or unnecessarily antagonise Obama's base should have little problem defeating the president.

The Chicago teachers' strike has ended after union activists accepted a negotiated agreement, bringing to a close more than a week of school-closures and allowing students in the nation's third largest school district to return to class.

Chicago mayor Rahm Emanuel raised the stakes in his confrontation with the city's teachers' union on Monday as he launched legal action to force teachers back to work.

"You want to run for president?" asked the New York Times columnist Frank Bruni in his book Ambling into History. "Here's what you need to do.

After months of deadlock and four days of strike action, Chicago teachers appeared on Thursday to be close to a deal with City Hall which would have children back to school by the beginning of next week.

Teachers in Chicago took to the picket lines for the first time in 25 years Monday after unions and the city's school district failed to reach agreement over a new contract.

As Republicans were promoting themselves as a multiracial party from the platform in Tampa two weeks ago, an ugly incident on the convention floor suggested not everyone had got the memo. From the podium a range of speakers of Haitian, Mexican, Cuban and Indian descent spoke of how their parents had overcome huge barriers so they could succeed in the US. In the audience, a successful black woman who works for CNN was being pelted with peanuts by a convention-goer, who said: "This is how we feed the animals."

As Obama speeches go it was plodding. As a man whose presidency was launched on a great convention speech, he can do better and we know it. Like a master sculptor he has proven his ability to take the raw material of a political moment and carve it rhetorically into something of aesthetic value that both engages and rouses.

Say what you want about Bill Clinton – and people do – but he gives good convention. And so he should. The last time he didn't address a convention was 1984. He knows which delegates' buttons to press because he sewed so many of them on himself.

Back in 1998, as the Monica Lewinsky scandal paralysed Washington, the Nobel laureate Toni Morrison inaugurated Bill Clinton as "our first black president". What Clinton lacked in melanin, the theory went, he made up for in earthly flaws, vicious enemies and folksy charm. His life read like a country ballad; but it just as easily could have been the blues. So when an actual black presidential hopeful showed up almost a decade later, there was bound to be friction. Not least when the candidate in question, Barack Obama, was challenging Clinton's wife, Hillary, for the Democratic mantle.

The atmosphere in Charlotte owed more to a renewal of marriage vows than a convention. Delegates arrived not ready to be convinced because they were already convinced and wanted to be inspired. To feel that, despite the contempt that comes with familiarity, infatuation that evolves into an enduring bond was still possible: that a crush would not curdle into cynicism. Outside, unemployment might be up, Guantánamo might be open and the deficit might be rising. But in the auditorium, hope had never died and change was still going to come.

Not long before Marco Rubio came out to introduce Mitt Romney on the final night of the Republican convention, some RNC staffers paced the floor carrying stacks of mass-produced “handmade” Hispanics Love Romney signs in search of people to wave them. This was no easy task. First, there were precious few Latinos there. Second, they come in all shades. In the border delegations of Arizona, Texas and New Mexico, there was little to distinguish a Hispanic who “loves” Romney from an Anglo who hates Hispanics. Days earlier, two attendees had been thrown out after pelting a black CNN camerawoman with peanuts and shouting: “This is how we feed the animals.” If the sight of a black woman with a camera could incite that much animus, imagine what rage might ensue if the wrong person were presumed Hispanic.

When I told people in New York I was moving to Chicago last year, they generally spent the first five minutes telling me how lucky I was. They emoted about "the lake" – Lake Michigan – which marks the city's eastern boundary; the eclectic skyline; the Frank Lloyd Wright architecture; the affable locals; the jazz scene; and the vibrant, self-sufficient neighbourhoods.