IT’S been six years since a heckler yelled “Iron my shirt!” at a Hillary Rodham Clinton campaign event shortly before the New Hampshire primary. Since MSNBC’s Chris Matthews called Clinton “Nurse Ratched” and commented on her “cackle.

” And since a guest on Bill O’Reilly’s Fox News show lamented that a female president would be undermined by “PMS and mood swings.”

If Clinton runs again, it’s doubtful that we’ll see the same level of sexist vitriol against her. And that makes me, well, a little sad.

If the misogyny flows as freely in 2016 as it did during Clinton’s first presidential run, the Republicans are doomed. They’re already in trouble with female voters, and it wouldn’t take much to erode that standing further.

So bring on the Todd Akins, the “life’s a bitch, don’t vote for one” T-shirts, the knee-jerk Hillary haters. This time around, it will only make her stronger.

The world of gender politics has changed in the past six years. The sexist swipes that were normal then won’t fly in a post-”war on women” culture. Feminism has hit a tipping point.

This month, Time featured a story on Clinton’s possible 2016 run, with Clinton represented on the magazine’s cover as a giant high heel trampling a tiny man. “Can Anyone Stop Hillary?” the headline asked.

The image, which played on old stereotypes reducing women to shoes and clothes, elicited some outrage but also much collective eye-rolling, because it felt like a throwback to another era. Slate’s Amanda Hess called it “sexist and hacky”; the Huffington Post and Marie Claire also denounced it.

Perhaps the biggest change surrounding women’s responses to political misogyny comes from the explosion of social media. Women on Twitter and Facebook shared their ire over the Time cover minutes after its release.

But, unlike most internet outrage, feminist internet outrage gets results. And it will give the Clinton campaign — and Hillary supporters — a weapon they did not have last time around.

The social-media power wasn’t available to feminists during Clinton’s first run. Three months after she announced her candidacy in 2007, Twitter broke 60,000 tweets a day; now there are more than 500m tweets a day from more than 200m active users.

Tumblr was barely a year old in 2008, and Facebook had just hit its first 100m users. Today, it has more than 1 billion.

Online takedowns of misogyny play a huge part in women’s political lives — and their votes.

A Gallup poll of 12 key swing states released shortly before the election showed that 60 per cent of women said government policies on birth control would be extremely or very important in influencing their vote.

“Every 2016 campaign will be run in an entirely new landscape, and that’s due in large part to the gains women have made politically since 2008, especially the gains made in 2012,” EMILY’s List President Stephanie Schriock told me.

“Republicans voiced their extreme and offensive views, and voters, particularly women voters, responded with one of the largest gender gaps in our nation’s history.”

Today, if someone tried to start a Facebook group called “Hillary Clinton: Stop Running for President and Make Me a Sandwich” — in 2008, this group had more than 40,000 members — it’s hard to imagine it would last long.

And if an opponent laughed it off when asked “How do we beat the bitch?,” as John McCain did at a 2007 event in South Carolina, he or she would be toast.

No doubt, there will be a tremendous amount of sexism lobbed at Clinton if she runs for president. It just won’t be as explicit or gleeful as in years past. At least, that’s what Republicans are hoping.

The GOP is so worried about further alienating female voters that it is sending its candidates to classes on how to talk to women — or, more accurately, how not to talk to them.

Remedial how-not-to-be-sexist classes will take the GOP only so far. When misogyny is part of your ideology, it’s hard to muzzle. But given the extra precautions, it’s likely that the misogyny directed at Clinton will be more sly than straightforward.

Much in the way the right race-baited its base in the last presidential election — Newt Gingrich calling Obama the “food stamp president” comes to mind — Clinton won’t be attacked directly for being a woman.

Instead we’ll see more subtle swipes about her emotions and temperament, like the headline after the Benghazi hearing: “Clinton explodes with rage.”

The good news for Clinton is that it doesn’t much matter if the sexism directed at her is tacit or explicit, or if it comes directly from politicians or just conservative talking heads. Because no amount of messaging or training or misdirection will change the fact that the GOP’s disdain for women’s rights isn’t a matter of language or talking points, but of policy.

Of course, feminists can’t rely entirely on the GOP shooting itself in the foot. We have to continue doing what we’ve recently succeeded at: exposing the damaging impact Republican policies have on women.

Still, something tells me that conservatives won’t be able to help themselves. After all, The New York Times reported last summer that Republicans are planning an anti-Hillary strategy that will “focus a spotlight on Mrs. Clinton’s age.”

I can’t wait.Jessica Valenti is the author of four books on feminism and a contributing editor at The Nation.

—By arrangement with Bloomberg-Washington Post