For Americans looking back on Sarah Palin’s unlikely 2008 vice-presidential bid, it must be hard to separate the real Palin from the Saturday Night Live parody. Ms Palin’s best-remembered line from that campaign is probably the claim, “I can see Russia from my house” – a quote not from Palin herself, but from Tina Fey, whose portrayal of the then-Alaska Governor on the long-running NBC comedy series was both devastating and strangely endearing.

SNL returns to US screens this weekend for its 42nd series, and it has cast a new performer to play Donald Trump: Emmy award-winning actor Alec Baldwin. Last year, the show was criticised for inviting Mr Trump to guest-host an episode, and for lampooning him as ridiculous rather than dangerous. Now that the preposterous property mogul is the GOP nominee – and not far behind Hillary Clinton in the polls – will the comedy be less kind?

Former SNL staffer Dean Obeidallah says TV comedians now have “a moral obligation” to tackle the more chilling aspects of Mr Trump’s candidacy. “Donald Trump is not a normal candidate. This is not Mitt Romney, not John McCain. This is a man who has trafficked in racism, sexism and bigotry,” Obeidallah told Politico.

People who will flee America if Donald Trump wins Show all 8 1 /8 People who will flee America if Donald Trump wins People who will flee America if Donald Trump wins Miley Cyrus 'God’ he thinks he is the f***ing chosen one or some shit! … Honestly f*** this sh*t I am moving if this is my president! I don’t say things I don’t mean!' Jemal Countess/Getty Images People who will flee America if Donald Trump wins Whoopi Goldberg 'I don’t think that’s America. I don’t want it to be America. Maybe it’s time for me to move you know' People who will flee America if Donald Trump wins Samuel L. Jackson 'If that mother**er becomes president, I’m moving my black ass to South Africa' People who will flee America if Donald Trump wins Raven Symone 'My confession for this election is, if any Republican gets nominated, I’m gonna move to Canada with my entire family. Is that bad? I already have my ticket. I literally bought my ticket, I swear' People who will flee America if Donald Trump wins Cher 'If he were to be elected, I'm moving to Jupiter' People who will flee America if Donald Trump wins Neve Campbell 'I’m terrified. It’s really scary. My biggest fear is that Trump will triumph. I cannot believe that he is still in the game ... [I'll] move back to Canada' People who will flee America if Donald Trump wins Jon Stewart 'I would consider getting in a rocket and going to another planet, because clearly this planet’s gone bonkers' People who will flee America if Donald Trump wins Randy Blythe 'He could just be a clown. If he is the president, though, I am leaving America 'till he's gone'

Earlier this month, Tonight Show host Jimmy Fallon was widely attacked for his chummy interview with Mr Trump. The most incisive moment of that encounter was when the comedian mussed the candidate’s hair.

This week, Stephen Colbert, host of the Late Show, expressed regret for having let Mr Trump off the hook in a September 2015 interview. “I tried being gracious and pointed at the same time, and got almost nothing out of him,” Mr Colbert told the New York Times. “It was actually boring, because he wouldn’t even look me in the eye. Being nice to a guy who isn’t nice to other people, it doesn’t serve you that much.”

On her show Full Frontal, Samantha Bee recently attacked her comedy peers and their network executive bosses for enabling the Trump campaign by inviting him to appear on their shows, “because ratings matter more than brown people.”

Ms Bee, HBO’s John Oliver and Seth Meyers of NBC’s Late Night have all been explicitly antagonistic to Mr Trump. But their shows – broadcast on cable or, in Mr Meyers’ case, very late at night – are preaching largely to the liberal choir. SNL, Mr Colbert and Mr Fallon reach the parts of America that they cannot.

The news media has been accused of facilitating the Trump phenomenon, first by mining the multi-millionaire’s notoriety for ratings, and lately for its role in “normalising” a candidate who is completely outside the historical presidential mainstream.

Similarly, comedians have struggled to effectively satirise a man whose real-life persona is so outlandish, and whose electoral success is so shocking. Accepting her sixth Emmy for starring as President Selina Myers in Veep, actress Julia Louis-Dreyfus said this month, “Our show started out as a political satire, but it now feels more like a sobering documentary.”

Making Mr Trump the butt of gentle jokes – a hair-muss, a dad dance – may also have contributed to his normalisation. In 2003, long before she ever portrayed Sarah Palin, Ms Fey told an interviewer that she was concerned Will Ferrell’s celebrated George W Bush impersonation had in fact helped Mr Bush to win the White House. “As much as we were making fun of Bush’s stupidity, Will also managed to make him seem almost charming and sweet,” she said.

Ms Clinton clearly appreciates the power of comedy to humanise a candidate. The famously defensive Democrat has made winning appearances on SNL and the spoof talk-show Between Two Ferns, with the latter apparently helping her to arrest a recent dip in the polls.

But then, might comedy be to blame for all this in the first place? Some have speculated that Mr Trump was motivated to run for the presidency after being mercilessly mocked by Barack Obama at the 2011 White House Correspondents Dinner.