The last two weeks of the campaign are going to be vital. Those who will never consider voting for the other side are now at roughly equal numbers. Both sides are sure theirs is the one that will own the White House come January. However, there are still tactics that are going to come in to play:
President Obama has an issue. He's traditionally had a bandwagon effect - When many were voting for him, more would jump on the bandwagon. Over time, bandwagoners fell off, only to be reinvigorated by his rather brilliant campaign team. As you can see from the chart, Obama's numbers have a tendency to fall over time only to have his campaign change the dialogue to something else. This happened in the last election, too.
This election was going to be harder no matter what: Last election, the Democrats had history on their side - The election became the tidal wave of popular support as a radical young black man from a single parent family in chicago came to end partisanship and be the true Washington outsider. Without that, his campaign has played brilliantly.
Benghazi became 47%, Paul Ryan's boost became the Democratic National Convention. His July trough became Romney's Taxes.
Final assessment: Expect something to happen in the week before the election and that advertisements will hammer it. It will be something new, and probably something that shows Governor Romney is the devil himself.
Governor Romney's issue is something very different. He's brilliant at raising campaign funds and he's also got strong 'fundamentals': He's running against a horrible economy, he's looks good on television(Which helped propel JFK in to office against Nixon) and he's got great bureaucratic skills.
He's also unable to connect to the voters the way President Obama has. He also is running against an anti-elitist mentality in the US that has resulted in several well-to-do governors failing in their bid for the presidency. If you don't believe this is an issue, look at John Kerry - He was a brilliant man from Massachusetts, like Governor Romney, only he was also a military veteran with three purple hearts, the silver star and the bronze star.
And he was running against someone who had disappeared for a year with no record during his military service.
People in the US get angry when others seem too good to be true, whether they're the incarnation of the song 'Fortunate Son' or a staunch war hero. They love their heroes, but they love more to see their heroes fall.
Final assessment: His campaigners are going to tell him, "Just keep your mouth shut, Governor. Keep hammering the fundamentals, do not address anything that isn't directly relevant to your bid for Presidency."
Between the two, the last two weeks will be, "Can the President find something to invigorate his base, whether it's demonizing Romney or making the President look good"?
If the President invigorates his base, he wins. If he doesn't, Romney wins.