Even though Brexit dominated her time at 10 Downing Street, Theresa May could not in the end deliver on her pledge to steer Britain out of the European Union, leaving her successor to try to finish the job. The problem is whether May’s replacement will have better luck in delivering what she could not.

In her almost three years in office, May, who said she will quit as Conservative leader on June 7, tried valiantly to deliver on the will of the people’s referendum and take Britain out of the EU while suffering as little damage as possible. But it soon emerged that unraveling 45 years of relations with the bloc was more complicated than previously thought and fraught with potholes.

The quest that consumed May’s tenure as prime minister began well enough. Although she was originally in favor of remaining in the EU, when she replaced David Cameron in 2016, she became a true blue leave advocate. It became quickly evident that leaving the EU became May’s obsession, as she made it a sacred, national and patriotic mission.

However, her painstakingly crafted deal with the EU on an agreement was rejected by both sides of the Brexit debate. Three times she went to parliament and three times the plan was defeated. In the first, May’s deal was rejected by 230 votes, the biggest government defeat in British parliamentary history. She tried again to get her Brexit deal approved, losing by 149 votes. A third attempt narrowed the margin of defeat to 48.

May simply could not collect the numbers she needed. Brexiteers felt her plan gave too much away and left Britain bound to EU rules. Pro-EU lawmakers wanted a softer Brexit that kept close economic ties to the bloc.

One of her biggest failures was of her own making. In June 2017, May unnecessarily held a snap election, thinking she could increase her parliamentary majority, which was 13, to something more like 100. A result like that would have given May a strong position from which to push through her Brexit strategy. No one seriously expected her to lose the election. But her plan backfired. She lost her Commons majority.

Still, she ploughed on, and “Brexit means Brexit” and “No deal is better than a bad deal” became her constant mantras, repeated almost ad nauseam. But she wore the label as a badge of honor. Even her harshest critics marveled at her ability to take the criticism and the pressure.

But her stoicism was not enough. After she had alienated many MPs by blaming them for the deadlock over Brexit, she was forced to finally accept that the Conservative Party, which did not elect her as leader, did not want her to serve any longer. Many Conservative lawmakers came to see May as an obstacle and blamed her for the UK’s failure to leave the EU on the scheduled date of March 29. The bloc has extended that deadline until Oct. 31 in the hope that Britain’s politicians can break their political deadlock.

Now, several contenders are lining up to replace May in a contest that will see a new leader chosen by Conservative lawmakers and party members by mid-July. The early front-runner is Boris Johnson, a former foreign secretary and strong champion of Brexit, but there are at least 16 other candidates at last count. The new party leader will become prime minister without the need for a general election.

A staunch Bexiteer will probably take over. But can he or she prevent Britain from crashing out of the EU without a deal before the October deadline? Can the new premier persuade the EU to renegotiate the deal that ultimately became May’s undoing? Theresa May’s departure has done little to allay the concerns of the EU, plus a hugely divided Conservative Party, parliament and country.