James Austin Johnson at Soho Theatre review: the SNL regular makes this look effortless

American import James Austin Johnson only arrived in London at the weekend, but he has already done his local research. There were bespoke references to Michael Gambon, The Only Way Is Essex and BBC4 in his effortlessly entertaining opening night set which seamlessly got the crowd onside.

Back home Johnson is renowned for his impressions of Donald Trump on Saturday Night Live that regularly go viral. Vanity Fair has called him the country’s best Trump impersonator and when he wheeled it out here it was easy to see why. He has the rambling and offbeat cadences so spot on close your eyes and you’d be so convinced Trump was onstage you’d be rushing for the exit.

Add in an equally effective whispering Joe Biden and it is clear that this young Nashville-born comic has all the essential political bases covered. And there is plenty more to enjoy here too in a show that takes in satire, autobiography, pocket-sized sketches, one-liners and songs. Not to mention an oddball worldview that is extremely appealing.

Routines cleverly segue into each other. The Trump take-down is linked to a riff about preaching. There was a sublime improvisation based on a fan’s TV programme suggestion as Johnson blended in mentions of The Marvellous Mrs Maisel so smoothly you could hardly see where the script ended and the ad libs began. I’m not sure if he’d have done so well if someone had shouted out EastEnders but he is so good he would probably have pulled it off.

His musical mimicry is the gift that keeps on giving. There is a note-perfect Elvis Costello, a priceless Bob Dylan pastiche and Willie Nelson doing Paul Simon. There is an extended send up of each member of supergroup The Highwaymen and don’t worry if you are not au fait with country rock specifics, Johnson helpfully fills in the blanks with mini-biogs for the uninitiated so nobody misses a joke.

Occasional gags were lost in translation, but this was his first Soho gig and he was clearly working things out in situ, swapping “bachelorette party” for “hen party” mid-story. I was not entirely convinced by his English accent. He thought it sounded like Alan Carr, it seemed somewhere closer to Cape Town to me. However, this is a minor quibble about a major talent.

This is not cutting edge comedy. Johnson is more gentle jazz comedian than rock and roll maverick. I did wonder if he is quietly thinking a Trump v Biden face-off would be good for his career, but he hardly needs to worry. His show is definitely not just about the voices of elderly politicians. Go and see for yourself.

Soho Theatre, to Saturday; sohotheatre.com