Chicago Mayor Rahm Emanuel took to the Democratic National Convention stage to defend President Barack Obama on Tuesday night – and to remind voters why they first supported his former boss in 2008.

Emanuel drew on his time as the president’s chief of staff to portray a decisive yet empathetic Obama, who made tough choices on national security and the economy, but who also read 10 letters each night from “every day Americans” to keep him grounded.

He also chronicled the difficulty of the early days of Obama’s presidency, with the economy in a slump and the continuing war in Iraq.

“We faced a once-in-a-generation moment in American history,” Emanuel said. “Fortunately for all of us, we have a once-in-a-generation president.”

After a week of nationally-televized Obama-bashing at the Republican National Convention in Tampa, Fla., four Illinois speakers helped kick off the opening night of the Democrat’s political convention.

Emanuel highlighted some of Obama’s policies that are popular with his Democratic base, such as the bailout of the auto industry and his decision to end the ban on gays serving openly in the U.S. military.

But Emanuel also defended some of the president’s more controversial policies, such as his federal health-care overhaul – a bill Emanuel himself helped muscle through Congress.

The mayor summed up his arguments in a refrain he repeated four times during his prime-time speech: “In case you forgot, that was the change we believed in, that was the change we fought for, that was the change President Obama delivered.”

Despite his pugnacious reputation, Emanuel mostly held off on attacking Republican presidential nominee Mitt Romney.