Women have been trying for decades to juggle, balance, multitask, lean every which way, work the second shift and, most elusively, have it all. For many working mothers, the guilt from being unable to fulfill any or all of these lifestyle euphemisms has been unrelenting.

Somehow men seemed relatively untouched by such work-life tensions. Their mission was merely to bring home the bacon, and bread-winning and parenting rarely appeared to conflict. In fact, while women typically suffer an earnings penalty upon having kids, men tend to enjoy a fatherhood pay premium. The result has been that family-friendly labor policies, as President Obama observed at the White House’s working families summit Monday, have traditionally “been thought of as women’s issues, which I guess means you can kind of scoot ’em aside a little bit.”

Until now. Steadily, and almost silently, work-life imbalance has thrown men off-kilter, too.

In fact, men now experience more guilt and frustration about balancing work and family duties than women do, according to a Harris poll released just ahead of the White House event.

The survey asked Americans about the flexibility and demands of modern workplaces. At one point, respondents were asked whether they agreed or disagreed with this statement: “I don’t get to spend enough time with my family.” Four in 10 mothers agreed, vs. almost six in 10 fathers. These numbers, I should note, jive with other recent data, including surveys from the Families and Work Institute, suggesting that men today experience more work-life conflict than women.

WASHINGTON, DC - APRIL 25: The Federal Election Commission meets on bring your child to work day on April, 25, 2013 in Washington, DC. Pictured, Executive Assistant Jonathan Borrowman holds his daughter, Grace, in the hearing room during a break. (Bill O'Leary/WASHINGTON POST)

I suspect a few factors are driving this newfound working-daddy guilt. But basically it comes down to the fact that men’s roles at home have finally evolved — and their jobs have not.

Women, including mothers of young kids, are much more likely to work today than a generation ago. As a result, most children live in households with no nonworking parents. That means when Little Liam has a fever at school, Mom is no longer the default choice for picking him up. Dad is getting those emergency calls at his office, too.

True, employed women still spend more time on housework and child care than even men without jobs do, but men are catching up. Once upon a time, being an active, involved father meant throwing a ball around with the kids on the weekends; today, whether by preference or necessity, men are spending more time on less leisurely, and less flexible, domestic duties. In 2010, for example, 95 percent of fathers said they bathed and diapered their kids at least several times a week, according to calculations from the White House’s Council of Economic Advisers.

Kids aren’t the only family responsibility butting into men’s careers. Ailing grandparents are playing a role, too.

Traditionally, women have borne the brunt of caring for elderly relatives. But thanks to longer life expectancies, smaller families (and therefore lower chances of having at least one daughter) and the rise of women in the workforce, men are increasingly expected or obliged to help out. And men who help care for elderly relatives are much more likely than women in the same position to be employed.

In the absence of access to flexible work arrangements and family-friendly benefits such as paid sick leave, many women have resigned themselves to part-time or otherwise less-demanding career trajectories, if they end up working at all. They have become, in Sheryl Sandberg’s terminology, comfortable with “leaning out.” In the Harris poll, for example, 50 percent of mothers say they had chosen to pass up a job they felt would conflict with family obligations, compared with 43 percent of men. Women’s propensity to “lean out” carries unsettling consequences, particularly for their ability to rise to leadership positions, but it is an effective way of reducing work-family conflict.

Men, on the other hand, seem to suffer from a sort of “masculine mystique”: being around for bedtime and ballgames has become increasingly important to them, but they still feel pressured to be their family’s primary breadwinner and to climb the corporate ladder. While women are finally starting to feel comfortable at least asking about more flexible work arrangements , men remain sheepish, fearful of looking like inadequately committed worker bees.

In a way, that men are wrestling with work-life conflict is a good thing — not because men deserve to suffer as women have but because if both halves of the population start demanding more family-friendly work arrangements and if amenities such as paid leave and flexible scheduling become crucial for attracting and retaining workers of both sexes, perhaps politicians and employers will finally stop scooting these “women’s issues” aside.