Avid political poll-watchers are finally noticing something they haven't seen for months in the largely flat-lined presidential campaign: Signs of movement. Starting about last Thursday, the last day of the Democratic National Convention, the national tracking polls from Gallup, Reuters/Ipsos, and Rasmussen each began showing an uptick for President Obama. By Sunday, all three polls had Obama up by four points over Mitt Romney. Since the rolling averages include some days before the Democratic convention ended, the bounce may get higher: New York Times poll guru Nate Silver says Obama could gain seven to eight points. "The bump is actually happening," says Ipsos pollster Julia Clark. "I know there was some debate whether it would happen... but it's here." What does it mean for the presidential race? Here, five theories:

1. Obama is now the frontrunner
This unexpectedly robust shift in the polls has very possibly "changed the composition of the race," making Obama a "reasonably clear favorite," says The New York Times' Silver. "All elections have turning points," and it's possible that the back-to-back conventions marked the moment when Obama broke away. And history isn't on Romney's side, says Nate Cohn at The New Republic. "No modern candidate has won the presidency without taking a lead after his own convention." More importantly, the polls "repudiate the view that a majority of voters are unwilling to re-elect the president, which is the entire basis for Romney's case for a come-from-behind, Reagan-esque sweep of undecided voters." Soon, "it might be time for a conversation about whether Romney can actually win."

2. But the bounce may be temporary
"It cannot be encouraging for the Republicans that after the first real apples-to-apples focus on the choice, Obama has surged," says Andrew Sullivan at The Daily Beast. But as Friday's weak job report highlights, the economy is still an albatross around Obama's neck. And it's worth remembering that "we've seen bumps like these before and they've usually been short-lived," says Doug Mataconis at Outside the Beltway. Just look at Romney's deflated bubble from picking Rep. Paul Ryan (R-Wis.) as his running mate. Despite Obama's bounce, you can bet that once November 6 rolls around, we'll be in "for a close finish," says Richard K. Barry at The Reaction — "just like we always thought."

3. Still, Romney needs to shine in the debates
Going forward, "Romney will have a money edge," and a large one if you count his allied super PACs, says E.J. Dionne in The Washington Post. Even with all that cash, though, "the debates next month are Romney's biggest opening" to reverse the polls. He was very effective in doing just that in his GOP primary race, and Obama "is out of practice." Even in 2008, debating was never Obama's "strongest suit," so there's real opportunity for Romney. This is one thing both campaigns actually agree on, say Jim VandeHei and Mike Allen at Politico: "Little movement in national polls before the first debate on Oct. 3, which both see as the most important day of this campaign."

4. And somehow, Romney needs to shake up the race
"Romney is the one who really, really needed the convention to shift the campaign conversation" his way, says Josh Marshall at Talking Points Memo. It didn't. He's never led in the polls, and the absence of a convention bounce for Mitt means panic time in Boston. I'd say, says Doug Brady at Conservatives4Palin. "Whatever momentum Romney was riding is long gone, and Team Mitt had better figure out how to generate... real, sustainable grassroots enthusiasm," stat. "Clearly his policy of ignoring Tea Party conservatives isn't working," and if he doesn't give up his bloodless campaign and publicly embrace conservative ideas, he's toast. Ugh, no, says Henry Blodget at Business Insider. "The extreme positions of today's Republican base are hurting, not helping, him." If he wants to broaden his support, he'll violently "shake his 'Etch-a-Sketch' again and become the fiscally conservative social progressive he was in Massachusetts."

5. Hold on. This contest is still basically tied
Everyone is jumping on a few daily tracking polls to build up Obama, and even "center-right scribblers and talkers" are discouraged with Romney's numbers, says Hugh Hewitt at his blog. Well, you know what? "There is something broken in polls, especially polls this far out from a presidential election." Look beyond these blips and the resulting hype, and it's clear that "the race among likely voters across the country is tied," as it has been for months. Once the dismal jobs numbers sink in, Romney will pull ahead. And while Obama "is not in immediate danger of retracing Jimmy Carter's career trajectory," says Walter Russell Mead at The American Interest, it's worth noting that "Carter was still the favorite at this point in the 1980" race. His "political ghost will be stalking the White House for a few more weeks," at least.

Read more political coverage at The Week's 2012 Election Center.