Nik Nanos digs beneath the numbers with CBC News Network's Power & Politics host Evan Solomon to get at the political, economic and social forces that shape our lives.

This week: The U.S. Presidential Race. Do women hold the keys to the White House?

The number:

42

That's the percentage of women who would support Republican nominee Mitt Romney if an election was held today.

The source: The Gallop poll was a random telephone survey of 9,565 registered voters. Conducted on a three-week rolling average ending Aug. 26, 2012. It's accurate to plus or minus 1.0 percentage points, 19 times out of 20.

A new Gallup poll shows Mitt Romney and Barack Obama in a dead heat. The poll gives each candidate 46 per cent of the vote.

But the poll also reveals a gender divide.  

Forty-one per cent of men would give their support to Obama, compared to 51 per cent for Romney. Fifty per cent of registered women voters would give their vote to Obama, compared to 42 per cent for Romney.  

"It's pretty clear when we look at long-term tracking numbers in the presidential race that it's been fairly stable and tight, except among the different genders," Nanos says.  

On Tuesday at the Republican National Convention, Romney's wife Ann reached out to women voters. But it's still unclear if the GOP will be successful.  

Nanos says the reality is that Republicans will not win the White House unless they do a better job appealing to women.  

Watch this week's Nanos Number segment, above.

Recognized as one of Canada's top research experts, Nik Nanos provides numbers-driven counsel to senior executives and major organizations. He leads the analyst team at Nanos, is a Fellow of the Marketing Research and Intelligence Association and a Research Associate Professor with SUNY (Buffalo).