New Jersey, with a 14-person House delegation, hasn't had any women in Congress since Republican Margaret Roukema left office Jan. 3, 2003.
In Pennsylvania, with 20 Senate and House seats, the only woman - Democrat Allyson Y. Schwartz of Abington - is on her way out, having run for her party's gubernatorial nomination and lost in the state's May 20 primary.
Three women who hoped to replace her (two Democrats and one Republican) also fell short that day, as did Shaughnessy Naughton, a Democrat who sought nomination in the Bucks County-centered Eighth District.
So, barring a major upset, Pennsylvania's delegation will become all-male when a new Congress begins in January.
"If you don't have [women] at the table, you don't really have the full representation of the state's population," said Kelly Dittmar, assistant research professor at Rutgers University's Center on Women in American Politics.
Academic experts and political consultants described a range of structural and cultural obstacles that confront female candidates.
The B word. Men who are aggressive or abrasive, qualities sometimes needed to win in politics, "are considered strong leaders," said Roginsky, a board member at Yale University's Women Campaign School. "Women who are aggressive or abrasive are considered bitches."
Where bosses rule. Congressional maps make most House seats safe for incumbents, who often serve for decades, leaving few chances for newcomers. When seats do open up, support for a replacement is often decided by local party organizations, generally still dominated by men.
Local party bosses have immense sway in both New Jersey and Pennsylvania, particularly in congressional races, which typically hinge on support in just one or two counties.
In statewide races, by contrast, New Jersey had a two-term female governor, Christine Todd Whitman, and Pennsylvania in 2012 elected Kathleen G. Kane as attorney general.
Of course, those races are also reminders of a non-gender factor: It takes good candidates to win. Both Kane and Whitman ran smart campaigns that won wide support.
"The party apparatus, while they talk about supporting women, it's more talk than real action," said Whitman, a Republican. "I don't think it's all sexism, but when the people that you spend your time with all look like you, you tend to support those people."
When it comes to breaking into the party infrastructure, women are more likely than men to vote and volunteer, but are less likely to write the big political checks that secure access and influence, said Dana Brown, executive director of the Pennsylvania Center for Women and Politics at Chatham University in Pittsburgh.
Party warlords, Whitman said, "let women run for offices that they think they won't win. That's what happened to me in 1990."
That year, in a race for the U.S. Senate, she took on a popular Democratic incumbent, Bill Bradley. "I got, basically, no support," she said. National Republicans pulled back a promised $300,000 ad buy 10 days before the election, Whitman said. She lost by three percentage points.
The close race provided a springboard to her gubernatorial run three years later, but Whitman still faced a primary fight, something she said would not have confronted a man who had done so well against Bradley.
Last year, another woman, former State Sen. Barbara Buono, was the Democrats' sacrificial nominee against Gov. Christie.
State-level success. State legislative seats can often be stepping-stones to Congress, but in Pennsylvania, women have struggled to win them. They hold 18 percent of the seats in the General Assembly, 38th among state legislatures, according to the Rutgers center.
"The way it has to start is, women have to decide, 'OK, we're going to start taking over [state] legislatures,' " said Neil Oxman, a Philadelphia-based Democratic consultant.
Schwartz went from the state Senate to Congress. In New Jersey, where women make up 30 percent of the legislature, Watson-Coleman and State Sen. Linda Greenstein leaped to the front of the Democratic field when Rep. Rush Holt, a Democrat, announced his retirement from Congress.
(Watson-Coleman's GOP opponent will be physician Alieta Eck, all but assuring that a woman will win at least one New Jersey House seat this fall.)
The will to run.Much more often than men, women need to be pushed to seek elective office, Roginsky and others said.
"Women are far less likely than men to be self-starters. The 'ask,' the encouragement of women, is even more integral in them making the decision to run," said Rutgers' Dittmar.
Kathy Boockvar, a Democrat who ran for Congress in Bucks County in 2012, knows that dynamic well.
"I can't tell you how many times that I've encouraged a woman to run for something - whatever it is, from township supervisor, to state representative, to Congress," Boockvar said. "And the first response is, 'I'm not qualified.' "
Also, she said, women tend to be more concerned about disrupting their families than men are. She was urged to run by Schwartz, among others - and initially declined because of concerns about the impact on her family.
Democrats have made appeals to women voters a central part of their campaigns, and in Washington much has been made of women's gains in Congress. Last year there were renovations to the women's room off the Senate floor - to better accommodate female senators, who now number 20.
But women still are just 18 percent of Congress - up from 10 percent 20 years ago.
"It is increasing," Dittmar said. "It's just increasing at a very slow and incremental pace."
Female lawmakers may push for a greater focus on women's health when it comes to funding medical research, or be more attuned to concerns about violence against women, to take two examples, said Chatham University's Brown.
When President Obama's health-care law was crafted in 2010, female lawmakers pushed to make insurers offer better maternity care, she said.
Boockvar worries about how the prospect of an all-male Pennsylvania delegation will affect younger women. When she ran in 2012, she said, the experience helped her teenage daughter dream about one day going to Congress.
"If they don't see any faces that are women," Boockvar said, "you could understand why that would reinforce a sense of 'That's not a place where I'm meant to be.' "