Republicans are outraged by Donald Trump's sexism - but why not his anti-Muslim bigotry?

"I would certainly implement (a Jewish database). Absolutely." "Donald J. Trump is calling for a total and complete shutdown of Jews entering the United States until our country's representatives can figure out what is going on." "I think Judaism hates us." "The Jewish ban is something that has morphed into an extreme vetting."

Donald Trump never said the statements above. If he had, his political career in 2016 would likely have collapsed – he probably would have been thrown out of the Republican Party, let alone be the GOP presidential nominee. But when you replace 'Jewish' by 'Muslim', and 'Judaism' by 'Islam', then he didn't just say some of those things. Trump said all of those things. And each time he said one of them, his polling ratings didn't diminish or deteriorate because of them. On the contrary – after more than one of those statements, his ratings increased.

Trump is an interesting figure, that probably history books will talk about as the great, white, chauvinistic populist champion of the early 21st century. There is no political figure in recent times that has come this close to occupying the executive branch of any country that is remotely as powerful as the United States, that holds such a breadth and width of utterly repugnant views. In that regard, it isn't just Muslims that Trump attacks – he's derogatory towards other groups in society, be they African-American, Latino, disabled, and many more.

But there is something uniquely problematic about the 'Muslim question' in this presidential race. From the outset, Trump's stance actually resonates with much of the Republican Party base – it's not unpopular. On the contrary, it is admired – and that raises a problem that will far outlive Trump's political career. Trump may be exacerbating anti-Muslim bigotry – but he's tapping into a bigotry that actually exists, and will be there beyond him.

When it comes to Republicans who are critical of Trump – and there are increasingly very many – the 'Muslim question' is often spared the same sort of scrutiny that other issues receive. That might be because those Republicans actually share his view.

There are many things to criticise Hillary Clinton on – but being somehow guilty of latent anti-Muslim bigotry isn't one of them.

But even for those who don't necessarily, it doesn't come up to the same level of scrutiny as their criticism on other issues. Compare the outrage in much of the Republican universe over, for example, Trump's views on Gonzalo Curiel, a federal judge of Hispanic heritage. No less than Paul Ryan, the Republican speaker in Congress, said: "I disavow these comments... Claiming a person can't do the job because of their race is sort of like the textbook definition of a racist comment. I think that should be absolutely disavowed. It's absolutely unacceptable." When the now infamous recording of Trump's talk on sexual assault came out last week, Paul Ryan was even more incensed.

Ryan is known, very clearly, as a critic of Trump – but when it came to Trump's 'Muslim ban', his comments were tepid in comparison to what he said about Trump on other issues: "I do not think a Muslim ban is in our country's interests." Imagine Ryan saying: "I do not think it's in our country's interest to claim a person can't do a job because of their Jewish heritage." You can't.

But Ryan went on to say something else. In reference to his opposition to the 'Muslim ban', "And so they're among our best allies, among our best resources in this fight against radical Islamic terrorism." Note this carefully – the case against a deeply and woefully immoral policy isn't made on ethical grounds. Rather, it's made on pragmatic grounds – that Muslims serve a 'purpose' in terms of American security interests and the fight against terrorism.

We're left wondering – if Muslims weren't involved in counter-terrorism activities – just like the vast majority of non-Muslims aren't involved in counter-terrorism activities, but simply suffer from the effects of terrorism like anyone else – would a 'Muslim ban' be less objectionable?

Now, Clinton doesn't make an argument like that – not in the slightest. On the contrary, many of her staff and confidantes make it clear that she went to substantial efforts – in many ways, more substantial than the current American president – to bring Muslim Americans into the DC establishment, and is clearly and fervently opposed to anti-Muslim sentiment. There are many things to criticise Hilary Clinton on – but being somehow guilty of latent anti-Muslim bigotry isn't one of them.

Trump is genuinely a threat to the fabric of American democracy.

But in responding to Donald Trump's missive about Muslims in Sunday's debate, Clinton followed an otherwise excellent response with a rather flawed one. After rightfully castigating Trump for his statements, in a way befitting a presidential nominee, she then went on to describe his rhetoric as 'shortsighted' and 'dangerous'. That America needed "Muslims to be a part of our eyes and ears". In that, very likely unwittingly, but nevertheless deeply defectively, Hilary Clinton implicitly linked American Muslim citizenship to a unique condition. Bill Clinton said something similar earlier this year, "If you're a Muslim and you love America and freedom and you hate terror, stay here and help us".

It's a condition that no politician has placed on, for example, white Americans, when it comes to reporting on far-right extremism, even though that remains to be a significant criminal threat within the United States. Citizenship is either universal or it isn't – and if it isn't, then it isn't actually genuinely citizenship at all.

Now, there shouldn't be any facetious equivocation between the two candidates in this regard, nor more generally. Trump is genuinely a threat to the fabric of American democracy – his threatening of his political opponent on Sunday is reminiscent of autocrats and dictators, not a politician in one of the most powerful and developed democracies in the world, let alone a contender for its executive office.

But after this election, the "Muslim question" in America will remain – and remain as one of the remaining forms of 'acceptable' bigotry in the American mainstream. That is a problem that goes far beyond Donald Trump.

Dr H.A. Hellyer of the Royal United Services Institute in London and the Atlantic Council in Washington DC, is the author of "Muslims of Europe: the 'Other' Europeans" and "A Revolution Undone: Egypt's Road Beyond Revolt". He tweets at @hahellyer.