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In every presidential election it seems, we try to isolate one voter group as key to the outcome. In reality, a victorious coalition is made up of voters from every demographic group. The winning margin is achieved through building up margins in key support groups, undercutting the opposition among their support groups, and appealing to independent voters of all kinds.

However, there is one group this year that, over and over again as you look at polls and emerging patterns, consistently pops up as crucial - white, middle-class women. Three months ago, I wrote a column on the importance of this group and used the analogy of amusement parks as a way to find and appeal to them along the way, especially in Ohio, Virginia, and Florida.

To carry this analysis and conversation a step further, let's try to isolate fundamentally where this election is likely to be decided. Now this isn't completely scientific (I will leave that to others with more computing power, more time and more resources), but it is a pretty accurate back-of-the-envelope discovery - not Nobel Prize worthy but definitely gag-prize heights.

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This election will be decided by the 10 percent of the electorate that have a favorable personal view of President Obama, disapprove of his performance in office (or are unsure), have an unfavorable personal view or are uncertain of Mitt Romney, who think the country is on the wrong track, and who aren't solid Democrats or Republicans. These voters right now are split between Obama and Romney - and they are very prone to swinging between the two candidates.

So right now, there is a small segment of voters who like the president, dislike Romney, but are voting for Romney because they think the country is on the wrong track. There are also voters in this 10-percent group who think the country is on the wrong track, but are supporting for Obama at this time. This is an interesting mix of voter sentiment that is not seemingly consistent, but that's where these voters stand.

And who are these 10-percent of voters who like Obama personally, disapprove of his performance, dislike Romney, and think country is on wrong track? Two-thirds of these key voters are white, middle-aged, middle-class women. Yep, that's right. More than 60 percent of the voters who will be decisive in this election are white women.

And understanding that dynamic, and understanding a bit of who they are, should give us a clue to what a winning message strategy might be. Obama and his campaign are going to need to maintain his personal connection with voters, not oversell the direction of the country because these voters think it's on the wrong track, and show how things might get better. They also need to keep Romney's personal rating from improving, which is why the Obama campaign is running mostly negative attack ads at this time.

Romney and his campaign should try to stay away from attacking the president personally and not try to make voters dislike Obama. Voters, like employers, have the capacity to let someone they like go if he isn't getting the job done. And Romney should look for opportunities to build a personal connection with voters and try to improve his personal rating, which is why we are seeing more of the candidate and his wife in interviews. The attacks on the president should be related to the country's direction and not some personal antipathy of Obama even though some in the Republican base are clamoring for that.

And most of all, remember that in tone and in substance, it is primarily white middle-class women each side needs to appeal to. These voters worry about the future, don't trust either political party, and have trust and loss-of-faith issues with both the institutions of government and corporate America. They lack a sense that either Obama or Romney has a vision for the future.

These voters today worry more about making ends meet and their children's future than the back and forth of the two political parties in Washington, which continually alienate them. The first candidate to crack this 10-percent group will move this race from dead even to a winning coalition.