LONDON—There was a point about halfway through this election campaign when Theresa May became a laughing-stock.

The nation edged past its boredom threshold and no longer found the prime minister’s platitudes to be mind-numbing—they were starting to become quite funny. She was becoming a parody of herself.

For months after moving into No. 10 last year she toured the country, offering virtually no insight into how she would deal with the aftermath of Britain’s European Union referendum. She had succeeded David Cameron because she was seen as a trustworthy figure who could make serious decisions in troubled times. Yet again and again, her only public explanation of the messy European divorce on the horizon was to keep repeating the words “Brexit means Brexit.”

When she called the election six weeks ago, she said she required a mandate to deliver Brexit. What Britain needed, she said was “strong and stable” leadership.

Fortunately, her Conservative party had a lead in the polls that stretched as many as 24 points ahead of Labour, in position to win a landslide victory and a 100-seat majority in the House of Commons.

“Strong and stable” was emblazoned onto the campaign buses, it was affixed to the front of her podium, and it was held aloft on placards at her events. She, and her Conservative colleagues, repeated the phrase in almost every interview, op-ed, and speech.

Reinforcing your core message is important to any political campaign, but this was getting ridiculous. It may have been Channel 4 News correspondent Michael Crick who caused the first crack in the façade. The PM stumbled into a policy announcement on social care funding that proved to be terribly unpopular. Instead of riding out the backlash, she opted for a sharp U-turn while trying to pretend she had done no such thing.

Directly to her face at a press conference, Crick compared May unfavorably to Margaret Thatcher, who once famously declared, “You turn if you want to. The lady’s not for turning.”

He suggested that she had done precisely the opposite. “Doesn’t this show that you are really weak and wobbly, not strong and stable?” he asked.

May fixed him with a glare, but the damage was done. The fact that “weak and wobbly” has since been picked up as a Labour Party talking point emphasizes the weakness of the Labour communications team but also reinforces how the remark has cut through with voters.

A week later, another venerable British reporter, Quentin Letts of the Daily Mail, was emboldened to say: “I don’t need to be rude but you seem to be a bit of a glum bucket. Are you enjoying the campaign? Will we see a bit more optimism?”

It won’t surprise you to hear that she replied by explaining that the country had a choice between the chaos of Labour's Jeremy Corbyn and the “strong and stable leadership” of her team.

Later that same day, May and Corbyn were to appear in an interview program in front of a live studio audience. Responding to the questions from renowned interrogator Jeremy Paxman, May delivered her well-rehearsed lines but the audience tittered and laughed at her.

“Seven times, they laughed at her during that debate,” trumpeted a Labour party spokesman. “It was extraordinary.”

Something had changed. Her authority was crumbling, and the opinion polls were tipping toward Labour.

“When you speak to senior Conservatives or people in the campaign they always knew that the public didn’t really know Theresa May yet she had incredibly strong fundamentals, people trusted her and they liked her and felt she was competent,” said Matthew Goodwin, author of Revolt on the Right. “Now they’re getting to know her and I think if you look at her performance against Paxman and the public she’s a way off being a polished performer. She’s very anxious, she’s quite nervous.”

The party had deliberately run a presidential-style, personality driven campaign because of May’s strong poll lead over Corbyn, but she was no longer looking all that strong and stable.

After the final town hall-style debate where May and Corbyn took turns to face questions from the audience, Labour candidate Andrew Gwynne said it was obvious May was uncomfortable when forced to explain herself.

“That’s probably why in the course of this six-week election campaign she’s actually avoided any real scrutiny from ordinary members of the public,” he told The Daily Beast. “She’s been in very small audiences of handpicked people and journalists dodging the real issues, dodging the real questions, and she falls to pieces, she cannot stand up to the scrutiny—she’s weak and wobbly.”

Conservative insiders have privately admitted that this has been one of the party’s worst-ever election campaigns. To make a personality play on a candidate without much of a personality has proved foolish, even though Corbyn’s record-breaking personal negatives made it tempting.

Beyond that overall strategy failure, there have been constant errors and missteps—along with two terror attacks in the midst of the campaign. May’s overtly political intervention on the steps of Downing Street the morning after the London Bridge attack will live long in the memory.

And this is where the serious damage has been inflicted on May. Few if any analysts expect that Corbyn will win the election and replace May as prime minister, but she will emerge from the campaign wounded.

Admittedly, some of the poor campaign narrative will be forgotten in the wake of a comfortable election win but there are plenty of pitfalls ahead.

“Let’s say she comes out with a majority of 30 to 35, that’s a disaster for the Conservative Party—that would be framed widely as a failure,” said Goodwin. “[Thatcherite Conservatives] will start positioning themselves immediately to cause her problems.”

Goodwin expects her to resign immediately if the Conservatives fail to secure an overall majority, but that remains a long-shot no matter what some of the polls are saying. The most likely scenario would see May stagger on into a second term never quite able to retain the authority she once grasped in her hand.