Hillary Clinton was 4 years old when she learned to hit back, so the story goes.

The girl who lived across the street in Park Ridge, Ill., was not quite a bully. But Suzy O’Callaghan could play “rough,” usually sending Clinton racing home, sometimes in tears. Finally, on one such occasion, Dorothy Rodham stopped her daughter at the door. “Go back out there,” she demanded, “and if Suzy hits you, you have my permission to hit her back. You have to stand up for yourself. There’s no room for cowards in this house.”

As she and her supporters tell it, Clinton’s been ready to take on a candidate like Donald Trump ever since the day she squared her 4-year-old shoulders and marched back over to Suzy’s. “I’ve been standing up to bullies my entire life,” Clinton likes to say.

As she’s turned her attention to the likely general election match-up, Clinton has increasingly sought to label Trump a “bully,” describing his campaign as an attempt to “bully his way to the presidency” and his rhetoric as reliant on “bigotry,” “bluster” — and “bullying.” It’s a familiar if not reflexive role for Clinton, a candidate often at her best when fighting back or under siege, performing well against opponents she’s cast in the past as bullies, most notably Rick Lazio, her competitor for U.S. Senate in 2000.

“Having known Hillary for 25 years, I know of no one tougher — no one who is more ready, willing, and able to take on a bully,” said Paul Begala, a longtime Clinton ally and an adviser to Priorities USA, the super PAC supporting her campaign.

But as the campaign engages the GOP frontrunner with more frequency and force, Clinton’s aides, friends, and former advisers also acknowledge that a head-to-head with Trump would be far less straightforward and predictable than it sounds when Clinton, echoing her mother, urges voters at rallies, “If you see a bully, stand up to him.”

Instead, allies are bracing for an ugly general election against a candidate the campaign is still struggling to nail down strategically. Trump is louder and more commanding of the news cycle than any “bully” Clinton has faced before, offering no clear historical precedent. (“She’s done pretty well against bullies,” as one former aide put it, “but this is a whole different stratosphere.”) Already a cause for unease is his willingness to venture aggressively and without apology into personal attacks and family matters, as he has in recent weeks against Ted Cruz and did against the Clintons last December.

“It makes me nervous. It makes me very nervous,” said Patti Solis Doyle, campaign manager on Clinton’s first presidential bid, on the question of personal attacks.

She added, “I calm down when I think about the electoral map and the potential blowout for Hillary.” (Less than 50% of Republicans support Trump, according to recent polling, and Clinton aides feel confident about facing a nominee who has already divided so much of his own party. Her pollster Joel Benenson told reporters on Monday that Democrats would see new opportunities to expand their battleground map.)

But when it comes to the recurring question of if, when, and how forcefully to respond to Trump and all that comes with his campaign, operatives have yet to work out a clear approach to Trump, three people close to the campaign said. And on the issue of the personal attacks in particular, “they really don’t” have a strategy, one said.

At points, Clinton has put Trump at the figurative center of her message — retooling her stump speech last month into an appeal for unity, with Trump as a foil. (The centerpiece line is a riff on his slogan: “What we need to do is make America whole again.”) On Wednesday, the campaign released an ad directed at Trump, targeting the divisiveness and violence that have accompanied his rise.

Yet, in other moments, faced with a new development or a pointed question, Clinton can shrink at first from a forceful response. Last month, Clinton's team of aides were still deliberating over a statement hours after violent and racially charged protests had broken out at a Trump rally in Chicago. The response released at 11:30 p.m. that night was seen as tepid and not directed squarely at Trump. Only the next day did Clinton address the Republican frontrunner’s role in encouraging the chaos in Chicago.

For now, caught between the primary and the general election, weighing in on Trump involves something of a careful balancing act: to continue to speak out, though often not by name, since, as aides often say, their “focus remains on the primary”; and to attack when appropriate, though not in a way that might invalidate the environment of anger felt by voters, or make it look like she’s down in the mud, or pick a personal fight.

Trump has already come at Clinton with the sort of insults he’s made a trademark on the campaign trail. He’s said Clinton lacks “stamina” and “goes to sleep” for “five or six days” between campaign trips. (“Hillary’s weak, frankly.”) He’s also called her “disgusting” for taking a bathroom break during a Democratic debate.

Trump unleashed his more personal attack late last year when Clinton accused him of a “penchant for sexism” for using a Yiddish vulgarity to describe her performance in the 2008 election. (“She got schlonged.”) What followed spanned all of about four tweets, an Instagram post, and one television interview, but Trump’s outburst against the Clintons — drawing on difficult questions about Bill Clinton’s sexual history and accusations that have been made against him — dominated coverage for days.

Trump accused the former president of sexist behavior, “a terrible record of women abuse,” and “a lot of abuse of women.” If the Clintons wanted to “play the woman card” against him, he said, “it's all fair game.” (“BE CAREFUL,” one of the tweets read.) Two weeks later, Trump called Bill Clinton an “abuser,” saying “a woman claimed rape and all sorts of things, horrible things,” and floated future attacks. "I don't want to say it's a threat, but it's a threat,” he said.

Months later, the memory of the Trump visitation still dangles somewhat uncomfortably over Clinton’s world of support. Earlier this year, the GOP frontrunner signaled that he would take his attacks even further. “I haven’t even started on her yet,” Trump said.

Clinton’s backers remain unsettled by the thought of personal attacks and what response they could provoke, particularly from Bill Clinton. Aides have stressed the importance of maintaining an even-keel to the former president, one former adviser said, knowing “there’s nothing that makes him more crazy than when people attack his wife.”

“Trump will say the most vile things to her one-on-one on a debate stage,” the adviser said. “And I don’t know how she’ll react to it, or how her husband will react to it, or how her daughter will react to it. There’s nothing he won’t say.”

In interviews, Clinton herself comes across as decidedly indifferent on the question of Trump’s personal attacks and what effect they might have. The answer? No effect at all, she’s said. When ABC News’s Cecilia Vega recently asked whether the possibility of a “very ugly and very personal” general election gives her any pause, Clinton responded flatly, “No, not a bit.”

“Your face doesn’t even move,” Vega remarked in disbelief.

“He can run whatever kind of campaign he wants. I have really thick skin,” Clinton said. “Look, if you have been around as I have all these years you are not surprised by anything and you are also not particularly affected by it.”

Clinton has described the adjustment to public life, first in the White House, and later on the campaign trail, as a hardening of sorts. In her memoir, Living History, she recounts entering her husband’s second term, “like steel tempered in fire: a bit harder at the edges, but more durable,” having undergone the defeat of her health care effort and the start of the Whitewater scandal. As a first-time candidate, throughout the 2000 Senate race, Clinton writes, “I had steeled myself for the possibility of personal attacks.”

Now in her second presidential race, there’s little that makes Clinton flinch on the campaign trail: a protester interrupting an event; a heckler at a small parade in New Hampshire, walking only paces away, screaming, “You’re a liar!”; even a voter at a town hall, abruptly posing a question about the women who've alleged her husband sexually assaulted them. Clinton greets it all with a straight and unmoved face, soldiering on as if nothing out of the ordinary has happened. (“I love parades,” Clinton told reporters after the New Hampshire outing last summer.)

On CNN last week, asked if she wanted to respond to Trump’s claim that she is “low-energy” and lacks “stamina,” Clinton declined. “No, I really don’t,” she said. “I don't want to respond to his constant stream of insults. I find it really, at this point, absurd.”

It’s possible that Trump may scale down the personal attacks in an effort to unite the party around his campaign. “The more he attacks that way,” said longtime Democratic strategist Joe Trippi, the less he helps himself with Republicans he’s already alienated.

It’s also possible he may lean into the attacks, hoping to rally support in Republican opposition to Clinton. Trump’s poor performance with certain types of Republican voters — including, notably, college-educated women — could pose opportunities for her if he continues with the personal attacks. Key general election voters may also take an unfavorable view toward the approach, Trippi said. “When you get into swing states and swing voters, those aren’t necessarily people who are into that.”

So far, Trump has yet to let up. Last week, he retweeted a side-by-side image comparing his wife, Melania Trump, to an unflattering picture of Ted Cruz’s wife, with the caption, "The images are worth a thousand words.” (Trump promoted the photo after wrongly blaming Cruz for an ad from an unaffiliated anti-Trump PAC one showing Melania posing nude for GQ.) The back-and-forth culminated in a National Enquirer item floating rumors about Cruz’s marriage — to which Trump issued a noncommittal response: “They actually have a very good record of being right. But I have absolutely no idea.”

Clinton, meanwhile, speaks eagerly about moving on to the next phase of the race. She occasionally tells voters at her events: The sooner the primary ends, the sooner “I can turn my attention” to the Republicans. Bernie Sanders has vowed to campaign through June, regardless of Clinton’s nearly insurmountable pledged delegate lead in the Democratic primary. (Sanders aides are now pursuing a strategy to catch up to Clinton by swaying super delegates to his side.) On Monday, during a conference call with reporters, Clinton pollster Benenson argued that by the last contests in April — slated for April 26 — the Sanders campaign will have simply run out of states.

Sanders has sharpened his attacks against Clinton — and run negative ads against her in key states. But Clinton allies have also weighed the benefits of an extended primary, which would delay a head-to-head contest with Trump. He, meanwhile, still must actually win the Republican nomination, as Cruz and John Kasich continue to campaign, and many Republicans talk up the prospects of a contested convention in July.

Her backers have traded theories on their best-possible outcome: a Clinton-Trump match-up now? Later? Or a “triangulation” scenario, as one put it, between Clinton, Sanders, and Trump — described by some as “ideal” and others, fearing hits from both sides, as “worst-case.”

For now, these aren’t questions that interest the campaign, at least not publicly: “We don’t have the luxury of spending a lot of time thinking about the different options of how things could turn out,” Clinton communications director Jennifer Palmieri recently told reporters.

And as for Trump? His attacks?

“From the first day of this campaign, there were 17 candidates attacking her everyday,” said Palmieri. “I don’t think that’s a new dynamic for us.”