After three straight lost elections, resulting in at least six straight years in the minority, Rep. Nancy Pelosi is facing her most uneasy moments in her 12 years as the top Democrat in the House. Reeling from their Election Day drubbing, House Democrats are still wondering exactly what went wrong and what they need to do to fix it.

“There’s a lot going on around here, privately, about the need for us to sit down and talk about the need to put a strategy together,” said Rep. Emanuel Cleaver II (D-Mo.), a former chairman of the Congressional Black Caucus.

Their leader is not ready to indulge the angst-ridden or frustrated members of her caucus. “It’s no use having a conversation unless you have data, unless you have analytics, unless you see what happened,” Pelosi (D-Calif.) said in an interview in her Capitol suite, dismissing calls for a marathon session just so lawmakers can vent. “I really have an attitude that some may not agree with: You have to know what you’re talking about.”

Pelosi has asked Rep. Steve Israel (D-N.Y.) to run a new policy and messaging shop to craft a formula for returning the party to the majority. Israel, who ran the caucus’s campaign arm for the past four years, has given presentations about the 2014 results, but some lawmakers want a broader review in which they can offer critiques.

Despite the irritability and questions among some of her members, Pelosi seems safe for now. No one challenged her for the leadership job, and her liberal base has even more leverage in the smaller caucus. Even her critics praise her fundraising prowess, and her loyal lieutenants have taken no visible steps toward taking over whenever the 74-year-old decides to retire.

Pelosi’s team is gathering information on the recent election: “It’s no use having a conversation unless you have data, unless you have analytics, unless you see what happened.” (Melina Mara/The Washington Post)

“She’s got an amazing reservoir of goodwill in the caucus. Who can do what she can do? The answer is nobody,” said Steve Elmendorf, a Democratic lobbyist who served as chief of staff to Pelosi’s predecessor, Richard A. Gephardt (D-Mo.).

At the same time, she remains a polarizing figure for Democrats in swing districts. According to Republican estimates, GOP committees and their outside conservative allies ran more than 80 campaign ads this year in dozens of competitive races that tied the Democrat to Pelosi.

On a drizzling, chilly Friday morning, Pelosi strode more than two miles around a park near her Georgetown condominium, analyzing 2014 and plotting for 2016. One mistake, she said, was not creating a distinct-enough message for House candidates and instead getting sucked into a national environment that turned against President Obama and his party.

“We have to analyze it brutally, honestly, about what works and what doesn’t work, and not assume that there’s going to be some overarching national message that’s repeated and echoed,” she said during the walk. Ready to go another mile, she stopped because she needed to head to the Capitol for meetings about next year’s agenda.

Going forward, she said, “we’re responsible for our own message and our own races.”

This is a key problem for House Democrats, because their party’s national strategy is now based on bringing out reliably liberal voters in urban areas. It has been successful for Senate races and for Obama. In the critical 2012 battleground of Ohio, for example, Cleveland voters gave Democrats a bigger edge than most experts thought possible, winning the state for Obama and holding a Senate seat.

But Democrats lost a House seat in Ohio that year, south of Cleveland. That scenario played out in many key states where safe House Democrats won by big margins and swing districts tilted Republican, leaving a comfortable majority for the House GOP in 2013 and 2014 that is growing even larger after a pickup of at least 12 seats.

Some House Democrats say the party’s agenda focused on small issues — such as increasing the minimum wage and guaranteeing equal pay for working women — that appealed to liberal constituencies but meant little to middle-class families in suburban districts.

“We are not talking about economics, and it’s beyond me,” said Rep. Richard E. Neal (D-Mass.), a senior member of the Ways and Means Committee who has asked staff members to draft broad economic proposals.

Another bloc blames Obama and Democratic leaders for not taking advantage of upbeat economic trends, including sustained job growth, decreased unemployment rates and sharply falling federal deficits.

“We Democrats are guilty of political malpractice with respect to the economic message,” said Rep. Gerald E. Connolly (D-Va.). “We persuaded the electorate that things are a lot worse than they really are.”

But there is also a liberal contingent that thinks the agenda was just fine and that things will improve in the presidential cycle when voter turnout increases. “We certainly don’t need some kind of re-branding, in my view. We could use some message sharpening,” said Rep. Jan Schakowksy (D-Ill.), a Pelosi confidante.

Those divisions have left Steve Israel in a bind, threading a needle between competing camps.

Armed with data from Geoffrey Garin, a leading Democratic pollster, Israel has acknowledged that the agenda needs to deal with the middle-class wage crunch, because the broad economy is surging while many workers aren’t seeing an uptick in wages.

“It’s my economy, stupid,” Israel said, tweaking the 1992 campaign phrase by consultant James Carville for a more personalized touch.

Pelosi thinks Democrats have until August to establish their trajectory, after which the presidential campaign will become all-consuming. She is dubious that a broad agenda could unite the eventual Democratic nominee and congressional Democrats.

Relations with Senate Democrats are in a deep chill. Pelosi called remarks by Sen. Charles E. Schumer (D-N.Y.), who questioned the timing of the 2010 health-care law, “beyond comprehension,” noting that as a House member in 1994, Schumer proudly wrote the assault-weapons ban that many blamed for the party’s 54-seat loss.

Pelosi also blames bad Senate campaigns in Arkansas, Colorado and Iowa for down-ballot losses. “Some senators even walked away from the president. That, I don’t get,” she said Friday.

There are signs of strain in the House. Last month, Pelosi pushed for her closest friend, Rep. Anna G. Eshoo (D-Calif.), to bump ahead in seniority to claim the top Democratic post on the Energy and Commerce Committee, a race against Rep. Frank Pallone Jr. (D-N.J.) that turned personal.

Pelosi alienated members of the black caucus, who were upset by a letter she wrote that pointed to a past example of a caucus member who had bucked seniority. At a dinner inside the Capitol, the black caucus heard from former members who rebutted Pelosi and said the path to power for lawmakers from poor urban districts was through seniority.

“They preached the gospel of seniority and probably had three to four converts right there,” Cleaver said.

Pallone defeated Eshoo by 10 votes. Pelosi played down her role but continued to reject seniority as beneficial.

“If they don’t want to choose the future and they want to be tied to seniority, they can use any excuse they want,” she said. “I will always fight the seniority fight because that is not a path to greatness.”

When Democrats gathered in mid-November for leadership elections, Rep. Bill Pascrell Jr. (D-N.J.) motioned to delay the ballot until a full airing of the 2014 elections could take place. He was rejected without a vote, and moments later Pelosi’s leadership team was elected without opposition.

Recognizing that many Democrats want her to expand her inner circle, Pelosi tapped Rep. Ben Ray Luján (D-N.M.), who is entering his fourth term, to replace Israel as chairman of the Democratic Congressional Campaign Committee — after a series of other names were floated for the post.

By the time her caucus retreats for a three-day gathering in Philadelphia late next month, Pelosi hopes to present a road map to win back the majority. For now, she just knows that voters did not hear the Democrats in the fall.

“That connection to voters was clearly not made,” she said, pacing along the Potomac River. “Look, I always say to people, ‘If your spouse doesn’t think you’re communicating, you’re not communicating. No matter how much you think you are, you aren’t.’ ”