K.K. Rebecca Lai and Allison McCann in the New York Times:
In the 2016 presidential election, 55 percent of white women voted for Republicans. And this year, the group backed Democrats and Republicans evenly.
Historically, women, people of color and young voters have been more likely to cast ballots for Democrats, while men and wealthier voters have tended to favor Republicans. These demographic divisions held in 2018, but the last few decades of exit polls show that that has not always been the case.
The gender gap has remained relatively consistent since the 1980s, but it has been widening in recent years. Political scientists attribute this to women placing more of an emphasis on social welfare issues like health care and child care, which generally align with the Democratic Party, whereas men are more concerned with issues like taxes and national security.