Obama faces another defining convention speech By Michael O'Brien , NBC News CHARLOTTE, N.C. - The Democratic National Convention comes to a close Thursday night with yet another defining moment for Barack Obama's presidency as he makes the case for his re-election to the nation. The president will take the stage at Charlotte's Time Warner Arena - a backup venue for the speech after the threat of inclement weather forced a cancellation of a planned open-air stadium event - with hopes of recapturing the magic of his convention speeches in 2004 and 2008. The Daily Rundown's Chuck Todd previews Thursday's DNC lineup, which includes speeches by Vice President Joe Biden and President Barack Obama. His first address as a keynote speaker rocketed Obama to political stardom, and his second, as a presidential nominee four years later, helped launch him into the White House. Tonight, he hopes to go three-for-three with another highly anticipated address. The president must soothe disillusionment over the promise of "change" that has not fully evolved. And the poor economy he inherited has only sputtered along. Obama will try to argue that Americans will be better off in four years than they would under Republican presidential nominee Mitt Romney, whom Democrats have pummeled repeatedly this week in an effort to transform the 2012 campaign into a "change" election. Former Arizona Rep. Gabrielle Giffords leads delegates in reciting the Pledge of Allegiance at the Democratic National Convention in Charlotte, North Carolina. "Hopefully, at the end of this convention people will say what we accomplished, what we needed to, and delivered our vision for the country and offer a clear contrast to what people saw in Tampa," Obama said Thursday on a conference call with supporters, before cautioning: "This is still going to be a really close election." Related: Obama apologizes to supporters for venue move The Democratic National Convention comes to a close Thursday night, as President Barack Obama is poised to make the case for his re-election to the nation. NBC's Andrea Mitchell reports. To do that, Obama will have to follow two nights of well-received speeches: Tuesday's by first lady Michelle Obama Wednesday's by former President Bill Clinton. He'll also have to clear the bars set by his keynote speech as a Senate candidate during the 2004 convention in Boston and his outdoor acceptance speech before tens of thousands of supporters at the Denver convention in 2008. Both of those speeches firmly established Obama as a formidable orator, and helped launch his political career to a new level. Tonight, the president is hoping his convention speech - which is regarded as one of a small number of crystallizing moments in a campaign - will help propel him into the final stage of his career: a second term. But that Denver speech has also become an object of ridicule for Republicans - a kind of shorthand for the hype they say had surrounded Obama's candidacy that year, typified by a stage featuring Greek columns. "You know, right here in Colorado, four years ago with the Styrofoam Greek columns, the big stadium, the president gave this long speech with lots of big promises," Republican vice presidential nominee Paul Ryan said Thursday in Colorado Springs. He said, let me quote, 'If you don't have a record to run on, then you paint your opponent as someone people should run from.' ... That is what he said four years ago and that is exactly what he is doing today. Republicans all this week have sought to portray Democrats as struggling to convince voters they're better off than they were four years ago, a well-worn campaign tactic used against embattled Democrats like Obama. The GOP has argued that a lack of enthusiasm - not the specter of thunderstorms - forced the president's campaign to move Obama's speech from the Charlotte Panthers" football stadium to tonight's much smaller venue. With Bill Clinton's anxiously awaited speech out of the way, all eyes now turn to President Barack Obama, who will make the speech that could make or break his re-election. Obama senior adviser Valerie Jarrett discusses. Many of the supporters who'd received tickets allowing them to attend the event at Bank of America stadium won't be able to fit inside the backup venue, a fact for which Obama apologized. My main message is, we can't let a little thunder and lightning get us down. We're going to have to roll with it," Obama said on his afternoon conference call. When the convention is gaveled in Thursday afternoon - with former Arizona Rep. Gabrielle Giffords expected to lead the pledge of allegiance - it is likely to pick up where Wednesday left off; that is, much of this week's convention has been nothing if not combative, a theme likely to extend through tonight's remarks and possibly into the speeches from Obama and Vice President Joe Biden. All this week, the Obama campaign has told reporters gathered at the convention that Americans watching the speech at home would have a clear concept of what a second Obama term would look like. Beyond that, few details have emerged. Many of the Democrats to speak have been scathing in their repeated criticism of Romney, characteristic of the Obama campaign's effort to transform the election into a "choice" between the two candidates rather than a simple referendum on Obama. "If Mitt was Santa Claus, he'd fire the reindeer and outsource the elves," former Ohio Gov. Ted Strickland said Tuesday in one of the week's most memorable lines. The featured prime-time speakers - San Antonio Mayor Julian Castro, Michelle Obama, Massachusetts Senate candidate Elizabeth Warren and Clinton - were more measured in their attacks on Romney before a national television audience, but nonetheless largely critical of the former Massachusetts governor. Some of the other featured speakers this evening include Caroline Kennedy, a scion of the prominent political family, and Massachusetts Sen. John Kerry, the 2004 Democratic nominee for president. Tonight's theme could turn at times toward foreign policy - an area in which Obama usually receives high marks in polls - in part due to Kerry, the chairman of the Senate Foreign Relations Committee and a rumored candidate for the secretary of state job in a second Obama term.