Editor’s Note: Luke McGee is a senior producer at CNN based in London.

London CNN  — 

Brexit has destroyed another British Prime Minister.

Three years after voters in the UK mandated their government to take Britain out of the European Union, Theresa May’s failure to do so has finally caught up with her.

“I have done my best,” she said in an emotional statement on the steps of Downing Street. But as she admitted, it wasn’t enough.

It always seems to end like this for leaders of May’s Conservative Party, divided for years over Britain’s relationship with the European Union. Hcer predecessor, David Cameron, quit the morning after 52% of the UK voted to leave the EU, having presided over his own political miscalculation.

Under her leadership, the Conservative Party has gone from being seen as the natural party of government to the exploding clown car of politics. Worse than being unable to govern, the Conservatives’ mishandling of Brexit has led to the public humiliation of the UK’s oldest and most successful political organization, suffering electoral losses to a rival party that didn’t exist six weeks ago.

May had previously said that she would stand down if her deal was approved, letting someone else take control of the next stage of Brexit. It turns out that top-to-bottom rejection of her deal and her leadership from pretty much everyone involved in politics would also do the trick.

May’s legacy will be defined by failures, public humiliations and catastrophic political miscalculations. Some of these were out of her hands. Some were the result of poor advice from those she chose to surround herself with. Some were because of the unprecedented political crisis that would come to dominate her time in Downing Street.

But much of it was her own fault. Many of her decisions had a directly negative impact on her ability to lead. The problem for May wasn’t just that British politics has been deadlocked for the best part of three years, but that she repeatedly engineered ways to erode her own authority.

By the time she accepted her number was up, she had lost the confidence of MPs, members of her own party and even her own Cabinet.

‘The nasty party’

Before taking the job, May had long been tipped for high office. In 2002, while serving as chair of the Conservative Party, May addressed the faithful at their annual party conference. At the time, the Conservatives had been out of power for five years. Tony Blair had successfully won over some traditional conservative voters and the party had an image problem. This also meant it had an electoral problem: “Our base is too narrow and so, occasionally, are our sympathies. You know what some people call us – the nasty party,” May said.

The speech went down a storm and paved the way for a new era. In 2005, the party would elect David Cameron as leader. Cameron knew the importance of May’s support, so made her a close ally and, along with other Tory moderates, oversaw a sweeping modernization of the party. It would come to be a party that believed in helping communities, the “Big Society”, and would eventually be the party that legalized same-sex marriage in the UK.

Former UK Prime Minister David Cameron with Theresa May in 2014.

Cameron became Prime Minister in 2010, albeit as leader of a coalition government with the center-left Liberal Democrats. Again, knowing May’s importance and her appeal to the more conservative members of the party’s base, he made her Home Secretary.

May was always considered one of the toughest members of Cameron’s Cabinet. As Home Secretary, she accused the Police Federation – the association that represents rank-and-file police officers in the UK – of “crying wolf” over budget cuts. She presided over a policy of creating a “hostile environment” for illegal immigrants. She even took on the EU on matters ranging from immigration to the deportation of high-profile terrorists. She was a force to be reckoned with and seen as one of the cornerstones of conservatism in a coalition compromised by liberals.

It was a shock to some when in 2016, May announced that she would be backing David Cameron’s Remain campaign. But her decision to do so, it turned out, was a masterstroke in triangulation. When Cameron resigned in the wake of the result of the Brexit referendum, May was seen as a safe pair of hands. She backed Remain, but her track record in the Home Office meant she was tough enough to stand up to the EU. She was the best candidate to unite two sides of the Conservative Party that voted for different things.

At least, that was the theory.

An alienating Prime Minister

Theresa May accepts the leadership of the Conservative Party in 2016.

However, from the moment she became Prime Minister, she began alienating people whose loyalty she would later regret not being able to depend upon.

In the months that followed May’s ascension to the top job, her Brexit position hardened. Rather than reach across the political divide within her own party, the Prime Minister’s embrace of Brexit was similar to that of the evangelism of a born-again Christian. Her new, ardent Brexiteer persona won her support on her own backbenches and in the Brexit-supporting media. The Daily Mail, an anti-EU newspaper, declared that May would “crush the saboteurs” who sought to frustrate Brexit.

While her new position as the defender of Brexit Britain won her some friends, it put off those who wanted a softer Brexit or no Brexit at all. But May and her advisors didn’t seem to realize how she was seen outside of the Brexit bubble.

This new confidence led to May and her inner circle making their first catastrophic mistake. In June 2017, despite having made little progress on Brexit plans, May held a snap election, convinced she could increase her parliamentary majority of 13 to something north of 100. A result like that would have given May an unassailable position from which to push through her Brexit strategy.

Her plan backfired. A limp election campaign in which May seldom appeared in public – and seemed hellbent on avoiding any members of it – made her look out of touch and power-hungry.

The opposition Labour Party took advantage. It managed to position itself not only as the more pro-Europe option, but its leader, Jeremy Corbyn, seemed more human. The Conservatives emerged as the largest party in Parliament, but May was stripped of her working majority.

From then, May couldn’t catch a break. Less than a week after her unnecessary humiliation, Britain was struck by tragedy. The fire that ripped through Grenfell Tower in London left 72 people dead and a community shattered.

Theresa May didn't meet Grenfell survivors when she visited the site of the fire.

May’s response was widely criticized. She visited the site, but didn’t meet with any of the survivors. It made her look cold and unsympathetic. While no one seeks to use a disaster like this for political gain, May’s woes were compounded by images of Corbyn hugging survivors. Even the Queen put on a better show.

Worse for May was that the Grenfell tragedy came to be viewed by many as the result of Conservative policies under David Cameron. Whether this was true or not didn’t matter: Labour was on the side of the people; May simply didn’t care.

Less than a week after Grenfell, the UK was struggling with another tragedy. A British man with a history of violence and fascination with anti-Islam ideas drove a van into a crowd of Muslims, leaving the Finsbury Park Mosque in London after evening prayers. When May visited the scene of the attack, she was heckled by bystanders. The political atmosphere in the country was becoming febrile.

May’s authority was under increasing pressure. Her election failure had forced her to sack her political advisers and enter into a supply and confidence agreement with the Northern Irish Democratic Unionist Party, who in theory prop up her minority government.

Theresa May accepted a cough sweet during a speech in 2017.

May was forced to face the music at the annual conference of her Conservative Party in October 2017. Her now infamous speech, in which she suffered a coughing fit, was confronted by a stage invader who handed her a P45 (the UK equivalent of a pink slip) was topped off with the set falling apart behind her. It came after days of mutiny from within her party, which numerous of the not-so-faithful publicly saying that it was time for May to go.

At this point, one might be tempted to feel sorry for the PM. But hold on a second. Sure, she can’t help a cough, a stage invader or bad set design. It’s very unlucky. But she could have avoided her fate of having to stand before a room of people utterly sick of her.

Brexit turns sour

It was around this time that her Brexit plan started to go badly. Meeting after meeting in Brussels resulted in EU officials and leaders publicly admonishing the UK’s Brexit negotiators.

Over time, May’s Brexit position softened as talks with the EU became friendlier and common ground was reached. But this is where May made another political error. While talks had been going well in Brussels, May’s Brexit plan was still a secret to many in London. It did not matter that the government and EU officials agreed on obscure but important details, whether the British public or political class would accept it was another thing altogether.

That failure to carry a divided House of Commons with her resulted in a deal being agreed that parliament came to detest. And that’s why, every time it was put to a vote, it failed.

Theresa May with European leaders in Brussels. They came to disrust anything she said.

This created problems for May both in London and on the continent. Over time, EU leaders simply stopped believing anything she said. The same goes for Brexiteers, who once saw her as their champion. The low point of trust in her own party perhaps came at a meeting of hardline Brexiteers last year, when members of her own party were heard chanting “Theresa the appeaser,” a reference to former Prime Minister Neville Chamberlain, infamous for striking a deal with Adolf Hitler in 1938.

Outside of Brexit, her time in the Home Office came back to haunt her more than once. First, the Windrush scandal. Her “hostile environment” policy had created legislation which required immigrants to prove their status by providing paperwork when trying to do everyday things like renting an apartment or taking a job.

Unintentionally, this hit a generation of immigrants from the Caribbean, who came to the UK in the post-war years to make up for a shortage in the workforce. Many of them were without paperwork and suddenly faced the threat of deportation, despite having lived in the country for decades.

Public outrage once again made May look out of touch and unsympathetic. It also meant that one of her arch-loyalists, Amber Rudd, was forced to quit as Home Secretary, the government department that oversees immigration.

Other decisions made during her earlier period in Cameron’s government have caused problems for May. The UK’s knife crime crisis has been blamed on cuts to police budgets she implemented. While the veracity of this claim is unclear, defending a policy of cutting police funding while parents are seeing their children murdered is not a good look.

But it was her mishandling of Brexit and poor political decisions that made governing impossible for May.

Cabinet support falls away

As the Brexit endgame drew closer, she was visibly losing the support of her Cabinet. After a meeting at the Prime Minister’s country retreat, Chequers, in which she outlined the latest Brexit policy position, she lost two important ministers. Boris Johnson, her Foreign Secretary and the most prominent Conservative Brexiteer, and David Davis, her Brexit Secretary, decided they’d had enough.

May had a problem. She needed to fill these positions with safe pairs of hands while retaining the Remain/Leave balance in cabinet. Dominic Raab, another prominent Tory would take over as Brexit Secretary.

Things calmed down for a bit and May was able to celebrate a huge victory on November 14, as news broke that an agreement had been reached with the EU. The Withdrawal Agreement was proof that there was a way out of the EU that didn’t cross the UK’s red lines and was acceptable to the EU.

The celebrations were short lived. Dominic Raab, May’s second Brexit Secretary, resigned less than 24 hours later. More followed. Her authority was falling apart in front of everyone’s eyes. The deal was hated in all corners of the House of Commons. Knowing it would suffer a heavy defeat, May held off holding a vote on the deal until January this year. She was handed the largest defeat in the history of the House of Commons – a margin of 230.

Meaningful Vote 2 didn’t go much better. May’s deal was defeated again on 12 March by 149 votes. Brexit was slipping out of her hands.

Nothing illustrates this better than the fact that in order for May to have a credible go at a third vote, she needed the EU’s help. At the March 22 EU summit, the 27 leaders of the other EU member states agreed to let May extend the Brexit deadline if her deal passed, and offered her two ways out of the mess.

Even that wasn’t enough to satisfy the House of Commons. Lawmakers went as far as trying to take the power out of May’s hands. For the first time in living memory, the legislative branch of government dictated the order of business on the floor of the House of Commons. The plan was to try and find a majority for an alternative to May’s plan. But isn’t just May that has a Brexit problem: the House of Commons has been very good at saying what it’s against, but useless saying what it’s for.

At the end of March, the PM made her final move. She told her Conservative lawmakers that if they backed her deal, she would go. May was throwing the kitchen sink at Brexit – and staking her entire career on it.

It didn’t work. Nothing May could offer was enough to avoid her final humiliation, as her own party tried to change its own rules to force her from office.

Another British Conservative politician, the divisive Enoch Powell, once said: “All political lives, unless they are cut off in midstream at a happy juncture, end in failure.” While May might be in good company on that front, it’s hard to think of another politician whose legacy will be so defined by catastrophe.