WASHINGTON – Having a Muskie moment isn’t necessarily a bad thing anymore.

Tears, once kryptonite to serious presidential candidates, today are more often seen as a useful part of the political tool kit.

Mitt Romney this week became the latest candidate to show his sensitive side. Tears welled in his eyes Monday as he spoke on the New Hampshire campaign trail about watching the casket of a soldier killed in Iraq and imagining that he had lost a son of his own. A day earlier, he choked up on NBC’s “Meet the Press” in speaking about his religion.

His campaign seemed skittish about two such episodes in as many days.

But for a candidate who sometimes comes across as cool and detached, showing a little emotion may not be something to cry about.

The nation has come a long way in the 35 years since a New Hampshire sob story ended Sen. Edmund Muskie’s 1972 presidential campaign. Muskie’s campaign slid off the tracks after it was reported that he had cried in response to a newspaper attack on his wife. He went to his grave maintaining that it had been melted snowflakes, not a tear, in his eye.

Fifteen years later, in 1987, former Democratic Rep. Pat Schroeder got grief for crying as she announced that she would not be a presidential candidate.

She’s still catching flak about it today, mostly from women.

“Oh, my gosh, I got a devastating e-mail about it from a woman writer just a couple of days ago,” Schroeder said in an interview. “I want to say, ‘Wait a minute, we are talking 20 years ago.’ It’s like I ruined their lives, 20 years ago, with three seconds of catching my breath.”

Schroeder says she used to keep a “crying file” on weepy politician episodes, but it got so huge she threw it out.

“Guys have been tearing up all along and people think it’s marvelous,” Schroeder said, pointing to episodes stretching back to Ronald Reagan.

But for female candidates, crying clearly is still in the no-fly zone.

Hillary Rodham Clinton is not allowed to cry.

At least not in public.

She is allowed to weep privately, though.

And maybe even tell us about it.

In her memoir, “Living History,” Clinton wrote about the moment her husband admitted his affair with intern Monica Lewinsky.

“I could hardly breathe,” she wrote. “Gulping for air, I started crying and yelling at him, ‘What do you mean? What are you saying? Why did you lie to me?”‘

But Clinton may shed no tears on the campaign trail. The same people who complain that she is cold and unemotional would seize on it as a sign of weakness and vulnerability, says Schroeder.

“For some reason,” she says, “we still are a little nervous for women.”

Aubrey Immelman, a political psychologist at the College of Saint Benedict and Saint John’s University in Collegeville, Minn., said women “are in a default position” in the crying game.

“It would have bad consequences for Hillary if she teared up in public,” Immelman said. “That’s unfair, but I think that’s probably how it still works in our society.”

For male candidates, Immelman says, whether crying is OK or not “depends on context.” Tough-guy candidates like Rudy Giuliani or John McCain, with his military background, can tear without fear, he says, and those talking about emotional issues such as fallen troops can emote without risk.

President Bush, for example, often chokes up in talking about the war dead, or visiting with the victims of natural disasters.

Former President Clinton was such an eager emoter, says Immelman, that he “had a reputation for turning on and off the emotion to serve his own ends.”

Romney, on the other hand, is seen as more stiff and formal. “For him to show a little bit of emotion could maybe soften that image a little bit,” Immelman said.

“I’m a normal person, I have emotions,” Romney told reporters. “I have emotion just like anyone else. I’m not ashamed of that at all.”

Clearly, Americans have mixed emotions about showing emotion.