A lot of supposedly "game-changing" things have happened, politically speaking, over the past 14 months: Osama bin Laden was killed, the economic recovery picked up and then faltered, the nation nearly shut down over the debt ceiling debacle, the GOP held its contentious primary, campaigns and super PACs have dumped hundreds of millions into campaign ads, and the Supreme Court upheld ObamaCare, to name a few. Some of these even occurred in the three months since the 2012 general election started in earnest between President Obama and his GOP challenger, Mitt Romney, but the "impact on the horse race: virtually none," say Dan Balz and Jon Cohen at The Washington Post. A slew of recent polls has the race within the margin of error, and a new Washington Post/ABC News survey has Obama and Romney deadlocked at 47 percent each — about where it has been for a year. With all the money, drama, and economic turmoil packed into the 2012 race, why can't either candidate pull ahead? Here, five theories:

1. Obama is saddled with the economy, Romney with himself
Michael Tomasky at The Daily Beast says, I agree with The Weekly Standard's Bill Kristol: Given the anemic economy, Romney should be trouncing Obama. Kristol thinks Romney needs to tell voters his plan to fix the economy, but "I think he has a bigger problem than the specifics: People don't like him. Romney could very well win, thanks to rich backers and "a few corrupt governors" rigging their states' voting systems in his favor, but "a likable guy who didn't pander so shamelessly and weakly to his party's radicals and seemed more at ease and empathetic would be six points ahead."

2. Voters don't know Romney yet
The tie at this point is bad news for Obama, whose massive early ad buys have failed to sway many voters, says Paul Mirengoff at Power Line. People seem to already know all they need to about Obama. Romney, meanwhile, has room to grow. "Barring unexpected economic news or some sort of major crisis, I don't expect either side to move the needle much until the Republican convention when, I hope, Americans will come to see Mitt Romney in a better light than that projected by the Democrats and their friends in the mainstream media."

3. Romney isn't hitting Obama hard enough
Team Romney has gotten a lot of flak from the elite conservative media and opinion-makers "for not being either tough or savvy enough" to pull ahead of Obama, and it looks like "the rest of the base might share those concerns," says Benjy Sarlin at Talking Points Memo. At a recent town hall in Colorado, for example, the first question was from a supporter suggesting that if Romney isn't up to the job, he should beef up his campaign by picking Rep. Allen West (R-Fla.) as his running mate: "We need a fighter.... [West] would make a great VP."

4. Almost everyone has decided how they'll vote
What the polls are really telling us is that there are very few undecided voters out there, says Chris Cillizza at The Washington Post. "Partisans — even weak partisans — have already been pushed into their respective camps, and there's very little evidence they plan to move." The two campaigns will spend the rest of the race "trying to figure out how to reach the 6 percent (or so) of people who have genuinely not made up their minds." That tiny number of true swing voters has held steady since "around 2000 or so, when we famously became a 50-50 nation," says Kevin Drum at Mother Jones. The 50-50 split is certainly true for this election. 

5. Voters are torn between the past and the future
The national polls are interesting, but it's a group of independent voters in a handful of toss-up states that will decide the election, say Cillizza, Jon Cohen, and Aaron Blake at The Washington Post. And in those states, the real split isn't between Obama and Romney but "whether they will cast their ballot this fall based on what the incumbent has done in his first four years in office or what he would do in a second term." Swing-state voters are evenly divided, with those fixated on Obama's first term leaning toward Romney and those focused on an Obama 2.0 backing the incumbent. So "what Obama needs is for voters to look forward. Romney needs them to look backward. And swing state voters have one eye looking to the past and one on the future."

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