(CNN) -- Now the Democrats are stepping into the spotlight. With the Republicans packed up from their stormy convention in Tampa, Florida, and back on the campaign trail, the Democrats gather in Charlotte, North Carolina, to explain to Americans why their candidate is a better choice in November. Like Republicans, Democrats must use this high-visibility media opportunity to outline their arguments for the fall. Although President Barack Obama is more of a known commodity than GOP candidate Mitt Romney after three and a half years in the White House, there is still a lot of work for Democrats to do in the coming days.
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Democrats hold their political convention this week in Charlotte, North Carolina
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Julian Zelizer says it's vital that Democrats respond to the charges made by the GOP
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He says Obama can't rely on blaming Bush or warning what a Romney White House would do
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Zelizer: Obama should strongly defend his record, including stimulus, health care law
Barack Obama
Obama
Obama
Outside of his strong favorability ratings, polls continue to show that @placeholder is extremely vulnerable as a result of the slow economic recovery.
Republicans
Republicans
GOP
GOP
With @placeholder talking about failed leadership, Democrats must seek to show this is not the case.
Democrats
Democrats
Democrats
Democrats
Democrats
Democrats
With Republicans talking about failed leadership, @placeholder must seek to show this is not the case.
Republicans
Republicans
GOP
GOP
Too often, Democrats have been on the defensive, explaining away the shortcomings of Obama's legislative legacy or blaming congressional @placeholder for the fate of his initiatives.
Republicans
Republicans
GOP
GOP
Obama has sometimes been reluctant to tell his side of the story, often responding to @placeholder criticism rather than laying out his understanding of what has happened.
Democrats
Democrats
Democrats
Democrats
Democrats
Democrats
The last argument that @placeholder, and especially President Obama, must make is that he has not given up on his vision of changing the way that politics works.
Republicans
Republicans
GOP
GOP
But in Mitt Romney's acceptance speech, the @placeholder candidate asked, "If you felt that excitement when you voted for Barack Obama, shouldn't you feel that way now that he's President Obama?"
Barack Obama
Obama
Obama
But in Mitt Romney's acceptance speech, the Republican candidate asked, "If you felt that excitement when you voted for @placeholder, shouldn't you feel that way now that he's President Obama?"
Barack Obama
Obama
Obama
But in Mitt Romney's acceptance speech, the Republican candidate asked, "If you felt that excitement when you voted for Barack Obama, shouldn't you feel that way now that he's President @placeholder?"
Republicans
Republicans
GOP
GOP
Even if many Americans still don't like Mitt Romney, and the tea party @placeholder make it hard for the GOP to appeal to the center of the electorate, Democrats, with this economy, have a million points of vulnerability.
Republicans
Republicans
GOP
GOP
Even if many Americans still don't like Mitt Romney, and the tea party Republicans make it hard for the @placeholder to appeal to the center of the electorate, Democrats, with this economy, have a million points of vulnerability.
Americans
They need to offer @placeholder something more than the status quo, something more than an alternative to what Democrats call radical conservatism.
Americans
They need to offer @placeholder policies they can believe in.