15 aren't up for re-election. Boxer is guaranteed to be replaced by a woman. Ayotte will either win or be replaced by a woman. Mikulski will almost certainly be replaced by a man. Murray is very likely to win.
That puts it at 17. The ones with at least a chance are Murkowski (AK), Cortez Masto (NV), Duckworth (IL), McGinty (PA), Ross (NC), Judge (IA), and Kirkpatrick or Ward (AZ). That puts the range from 17 to 24. Likely I'd say 0-1 pickup.
Murkwoski will win reelection. That's almost a given. Her most credible primary challenger dropped out after only 7 days or so in the race. She's pretty popular in the state, it seems (having won as a write-in candidate in 2010). Nevada is a tossup right now, Duckworth is the favorite, Ayotte does have a primary challenge, but men are unelectable to New Hampshire seats so that doesn't matter, Toomey, Burr, Grassley, and McCain are all favored at the moment. So let's assume Maryland and Illinois cancel each other out, and leave Nevada as a tossup. I predict 18 women at the start of the 115th Congress.
