Los Angeles Mayor, Eric Garcetti, has a favourite mantra. Twenty-three American states, he likes to tell interviewers, have a population smaller than the city he runs.

This is no mere boasting about America’s biggest city. Instead, Mr Garcetti is advertising his executive skills as he prepares for a possible run for the presidency.

In its 230-year history, America has elected vice-presidents, governors, senators, generals — and Donald Trump – to its highest office. It has never sent a sitting mayor to the White House.

Mr Garcetti — who became Los Angeles’ first elected Jewish mayor and only its second Mexican American in 2013 – appears keen to break the tradition.

“I hope some mayors run [for the presidency],” he suggested recently, as he refused to quash speculation that he intends to throw his hat into the ring.

This year, he has visited such battleground states as Florida, Wisconsin and Nevada — as well as New Hampshire, which holds the all-important first primary of the election season.

He is also assiduously raising his national media profile and churning out a string of pronouncements on the kind of issues — immigration, federal taxes and job creation — that voters expect aspiring presidents to have a view on. The gambit is paying off: the Washington Post named him as one of the 15 possible Democrats to take on Mr Trump in 2020.

There are, however, a multitude of hurdles on the road to the White House. Mr Garcetti previously represented Hollywood on the city council and may be easily typecast as a West Coast liberal by the Republican attack machine. Americans may also baulk at the idea of electing a relative unknown whose biggest achievement to date is helping LA win the 2028 Olympics.

At the same time, commentators note that the election of a billionaire reality TV star has changed many assumptions about what voters will and won’t wear.

The 46-year-old Mayor’s description of himself as part of “an impatient next generation” provides a none-too-subtle contrast with the 70-somethings — former vice-president Joe Biden and senators Bernie Sanders and Elizabeth Warren — who are often touted as 2020 Democratic candidates.

Mr Garcetti already deftly deploys a series of alliterative turns of phrase to help him navigate the ideological minefields which litter American politics. He rails against both the “immorality” and the “impracticality” of the Trump White House, casting himself as “progressive and practical”.

His father – a former district attorney – is of Mexican descent, while his maternal grandparents were Russian Jewish immigrants. The mayor thus jokingly refers to himself as a “kosher burrito”.

“I always felt myself to be Jewish and Latino very comfortably,” he said prior to his 2013 campaign. Weekends were filled both with bowls of menudo and lots of bagels.”

The family was secular but Mr Garcetti — a member of LA’s IKAR synagogue — says he “came to my faith in college.

“Judaism helps me think through the world both ethically and intellectually,” he has argued, influenced by his “fearless” maternal grandfather Harry Roth, who founded the Louis Roth clothing brand.

Roth was President Lyndon Johnson’s tailor but was strongly opposed the Vietnam War. He took out a full-page advertisement in the New York Times calling on the president to withdraw the troops, knowing he would never be invited back to the White House.

It’s not hard to imagine what the current occupant of the Oval Office would make of such behaviour.