On Election Day, there will be at least 12 women running for the United States Senate in 10 different races. Most are Democrats, but not all; Republicans could see the addition of four more women if everything falls their way.

Many students of politics tend to assume that voters will lean toward candidates that, well, look like them. A look at the most recent polling in four of the aforementioned races, though, applying that assumption to female voters yields widely varying results, with one theme: Women are more likely to back Democrats.

Ernst on election night. (AP Photo/Charlie Neibergall, File)

The races we looked at were ones in which 1) there was good polling, 2) the polling had demographic breakdowns, and 3) the results were fairly recent. That gave us these four:

For each poll, we looked at net support for the female candidate by gender and party registration. (In other words, if 50 percent of women supported the candidate, and 42 percent supported her opponent, she had a net 8 percentage point support.) The results are below. Can you spot the candidate that's a Republican?

Alison Grimes in Kentucky barely gets more support from women; she trails. Shaheen romps with women and leads Scott Brown handily. This makes sense: Each gender is half of the voting population. What's more, looking at gender and party, it's clear that there's a correlation between the two. In each case, positive support from Democrats occurred simultaneously with positive support from women, and vice versa. Ernst, in Iowa, faces opposition from women -- because of her party, not her gender.

It gets more interesting when you compare each state with how it voted in 2012. We looked at exit polls to figure out net support from women for the Senate candidate's party in the last presidential election versus support for the current candidate.

In the three scenarios (Kentucky didn't have available exit polls), three different things happen. Ernst is outperforming Mitt Romney among women by four points. (Which continues a trend.) Hagan, in North Carolina, is doing slightly worse than President Obama did. Shaheen is doing much, much better.

There are a lot of reasons for this. The three women face very different opponents, for one thing. And those opponents are performing at various levels of glitchiness.

In the North Carolina poll, there's a bonus: gender/party breakdown in the question of support for each candidate. Here's how men and women in each party view Hagan.

Republican women are less likely to back Hagan than Republican men. For independents, it's even.

This is a small sample size in one poll that reinforces the main point: Gender is not a silver bullet in winning an election. But for Democrats, turning out as many women as possible would be a very good idea.