With the morale of its employees lingering at the bottom of government rankings year after year, the Department of Homeland Security seems to be Exhibit A for weaknesses in management and leadership.

On Wednesday, impatient House lawmakers pressed a top agency official to tell them when things would get better.

“Y’all are last,” Rep. Mick Mulvaney (R-S.C.) told Angela Bailey, the DHS personnel chief, at a hearing before a panel of the House Oversight and Government Reform Committee. “All we want to know is, when is it going to get better?”

“My question is, when are we going to have accountable leadership, and if we don’t, who is going to pay the price?” the congressman, increasingly exasperated, asked Bailey. “Right now it’s the employees and the public.”

Bailey said she expected a number of DHS morale-boosting efforts —town hall meetings with employees, a new emphasis on feedback to bosses, an employee steering committee dedicated to fairness in hiring and promotions — should result in better scores on this year’s annual survey of the federal workforce.

But the reality was clear to lawmakers and the group of personnel leaders who testified before the committee’s panel on government operations: As vital as a happy workforce is to a well-run, responsive government, the formula for what’s been dubbed employee engagement is harder to grasp.

The annual Best Places to Work in the Federal Government rankings for 2015 found a continuing struggle across government to improve leadership and the engagement of employees in their jobs. After a government shutdown, budget cuts known as sequestration and a three-year pay freeze, a steady drop in morale that began in 2010 may finally have bottomed out, the survey showed.

After hitting a four-year low in 2014, federal employees’ overall satisfaction with their leaders and supervisors and work experience rose 1.2 points last year to 58.1 percent. But 58.1 percent is not especially high.

The Obama administration’s effort to improve job satisfaction has had mixed results, with the Labor Department, the Department of Housing and Urban Development and other agencies showing real improvement and others still stuck at the bottom.

Rep. Gerald Connolly (D-Va.), chief Democrat on the government operations panel, cited an agency’s mission as the “dispositive factor” in determining morale. DHS was cobbled together from disparate agencies after the terror attacks of Sept. 11, 2001, while the mission-driven NASA continuously ranks at the top of the Best Places survey. But the founder of the survey countered that argument before the lawmakers.

“It’s not the mission,” said Max Stier, chief executive of the Partnership for Public Service, which publishes the Best Places rankings with Deloitte. “It’s leadership.”

Stier and Connolly agreed that many federal agencies do not reward high performers, which can reduce their ambitions.

“We don’t have a culture of performance recognition in government,” Stier said. “That’s why many employees are risk-averse. You see a downside and no real upside.”

Sydney Rose, chief human capital officer at the Labor Department, the most improved large agency in the rankings for two years running, said leaders there have made several changes to boost morale. One is offering employees temporary details to new projects or offices. The other is as simple as adding  microwave ovens in the cafeteria.