In the House races, where women have sided with Democrats by an average of nine points since 1976, they are now about evenly split between Democrats and Republicans, in the latest Washington Post-ABC News poll. That is a sharp drop-off from just four years ago, when women chose Democrats by a large 12-point margin and put them in the majority.

Of course, the news is not good for Democrats almost everywhere – and certainly much worse among white men, who are embracing Republican candidates by a greater proportion than ever before. But the women matter more: As a whole, men lean Republican, while women usually act as a counterbalance for Democrats.

“Women are not a shrinking piece of the electorate. They’re a shrinking piece of the Democratic pie,” Lee Miringoff, director of the Marist Institute for Public Opinion, said, refuting the notion that female voters are simply unmotivated like the rest of the Democratic base. Celinda Lake, a Democratic pollster, said Democrats are seeing an erosion with women who did not attend college, especially because of the economy…

Smith credits Sarah Palin – who endorsed Ayotte in the primary – with helping shift a decades-old dynamic. Where suburban women were a core part of the Republican party in the 1960s and ’70s, they shifted to the Democratic party in the 1980s and 90s, and have been a core part of the Democratic base ever since.