Louisville, Kentucky (CNN) -- In the big drama this election year -- whether Republicans will take control of the Senate -- the answer may rest in the hands of women candidates.
Especially after Tuesday's primaries.
Women contenders grabbed headlines from a primary victory in Kentucky, where Democratic nominee Alison Lundergan Grimes emphatically told supporters: "I am not an empty dress," to Oregon, where Republican hopeful and pediatric neurosurgeon Monica Wehby touted her own qualifications for Senate: "I am a doctor, a mom."
And in Georgia, the retirement of a Republican senator drew an unexpectedly popular would-be Democratic replacement in Michelle Nunn, who boasted that "Washington is going to learn a thing or two from our campaign."
Add these candidates to the list of vulnerable female senators in Louisiana, North Carolina and New Hampshire and it's clear the balance of power in the Senate could depend on how women candidates in both parties fare.
In no place is gender more at play than in Kentucky, where Grimes is running a fierce challenge to Senate Minority Leader Mitch McConnell.
"I am a strong Kentucky woman who is an independent thinker," Grimes told supporters Tuesday night.
Grimes is already leaning way in -- using her gender to appeal to female voters, who make up more than half the Kentucky electorate. And she's playing up the fact that polls show 30-year Senate veteran McConnell is especially unpopular with women.
On the eve of his Republican primary, we asked McConnell whether he suffered from a gender gap problem.
"We'll find out in November, won't we?" McConnell said. "I mean, the point is women in Kentucky have been treated just as badly in this environment as men have."
But McConnell's overt appeal to women belies that bravado. In his victory speech Tuesday, the most powerful Republican in the Senate spoke glowingly of both his late mother and his wife Elaine Chao, a former cabinet secretary under George W. Bush.
And McConnell told the stories of three Kentucky women he said were hurt by President Barack Obama's health care law.
Democrats' other big hope for picking up a GOP Senate seat is Michelle Nunn, daughter of veteran Sen. Sam Nunn, in Georgia.
"I believe that change is possible," she said in a speech on Tuesday.
As for Republicans, Monica Wehby is a pediatric neurosurgeon hoping to unseat Democrat Jeff Merkley in Oregon, running as a political outsider.
"I'm not a career politician," Wehby said in a speech Tuesday night.
Republicans are favored to pick up a Democratic seat in West Virginia with Shelley Moore Capito, but even if she loses to Democrat Natalie Tennant, either way the state would elect its first female senator.
There are currently 20 women senators, a record but still far from representative of the country, which is more than 50% female. 2014 could mark another historic number.
CNN's Rachel Streitfeld contributed to this report