If it seemed strange for the president of the United States to engage in a Twitter spat with the mayor of London—a city that on Saturday night experienced the U.K.’s third terrorist attack this year—the feud did at least have a historical context. In fact, President Trump and London Mayor Sadiq Khan have been bickering in public since about a year and a half ago. Their feud can be traced to Trump’s call as a presidential candidate, following the attacks in Paris in November 2015, for a ban on Muslims from entering the U.S. A month later, following the attack in San Bernardino, California, Trump called for a “total and complete shutdown” of Muslims entering the country.
In May 2016, Sadiq Khan became London’s first Muslim mayor. Writing in the Observer that same month, Khan, the son of Pakistani immigrants to the U.K., accused David Cameron, then the prime minister, and Zac Goldsmith, Khan’s Conservative rival in the often-nasty mayoral race, of employing tactics “straight out of the Donald Trump playbook”—a reference to his rival’s attempt to paint him as an extremist.
When asked by Time on May 9 after winning the mayoral race, “What’s your view on a potential Trump presidency given his remarks on Muslims?” Khan replied:
Clearly [I’ll visit] before January in case Donald Trump wins ... I want to go to America to meet with and engage with American mayors. If Donald Trump becomes the President, I’ll be stopped from going there by virtue of my faith, which means I can’t engage with American mayors and swap ideas.
That same day, The New York Times asked Trump, at the time still a presidential candidate, what he thought of Khan’s victory. Trump said he was “happy” that London had elected its first Muslim mayor, and said “there will always be exceptions” to his proposed travel ban on Muslims. Trump also said Khan’s victory was a “very good thing … because I think if he does a great job, it will really—you lead by example, always lead by example. If he does a good job and frankly if he does a great job, that would be a terrific thing.”