Legal experts and LGBT campaigners have condemned the Trump administration's draft executive order on religious freedom as "unconstitutional" and "un-American".

The leaked four-page draft, obtained by The Nation and The Investigative Fund, overturns a wide range of anti-discrimination protection for minorities and is likely to delight conservative evangelicals and outrage liberals in equal measure.

If enacted, the document would create wholesale exemptions for people and organisations who claim religious or moral objections to same-sex marriage, premarital sex, abortion, and transgender identity, and it seeks to curtail women's access to contraception and abortion through the Affordable Care Act.

It seeks specifically to protect the tax-exempt status of any organisation that "believes, speaks, or acts (or declines to act) in accordance with the belief that marriage is or should be recognised as the union of one man and one woman, sexual relations are properly reserved for such a marriage, male and female and their equivalents refer to an individual's immutable biological sex as objectively determined by anatomy, physiology, or genetics at or before birth, and that human life begins at conception and merits protection at all stages of life".

Marty Lederman, a professor at Georgetown University Law Center and an expert on Church-state separation and religious freedom, told The Nation: "This executive order would appear to require agencies to provide extensive exemptions from a staggering number of federal laws – without regard to whether such laws substantially burden religious exercise."

Lederman said that the exemptions could themselves violate federal law or license individuals and private parties to do so. He added: "Moreover, the exemptions would raise serious First Amendment questions, as well, because they would go far beyond what the Supreme Court has identified as the limits of permissive religious accommodations." He said it would be "astonishing if the Office of Legal Counsel certifies the legality of this blunderbuss order."

Jenny Pizer, senior counsel and law and policy director for Lambda Legal, said the draft order would appear to violate the Establishment Clause by listing a "particular set of religious beliefs and giving special government protection to people who hold those beliefs as opposed to different beliefs." Pizer added that the draft order constitutes "a licence to discriminate with public money in a series of contexts in which people tend to be vulnerable," such as against LGBT children in foster care, which is federally funded.

Meanwhile Chad Griffin, the president of the progressive Human Rights Campaign, called the draft "sweeping and dangerous." He told ABC news: "It reads like a wish list from some of the most radical anti-equality activists. If true, it seems this White House is poised to wildly expand anti-LGBTQ discrimination across all facets of the government – even if he does maintain the Obama [executive order from 2014]. If Donald Trump goes through with even a fraction of this order, he'll reveal himself as a true enemy to LGBTQ people."

Joining him, Sarah Kate Ellis, the president of gay campaigning group GLAAD, called the policies "unconstitutional and un-American". She said: "If anything in this document were to become federal law, it would be a national licence to discriminate, and it would endanger LGBTQ people and their families...Freedom of religion does not mean the freedom to discriminate. If the Trump administration moves forward with any of these unconstitutional and un-American policies, the chorus of public outcry will get even louder while the president's approval ratings continue to crumble."

The order may well (or may not) be unconstitutional. Yet Trump knows that he is appealing to the Christian right – both evangelicals and white Catholics – who helped propel him into office.

The Christian right has been slow to react to the draft, careful, perhaps, not to show glee and further infuriate the liberal left in the face of such controversial policies. For some, it may be a case of 'too good to be true'.

The outlet which obtained the leaked document is worth noting. Founded in 1865, The Nation is the oldest continuously published weekly magazine in the US and the most widely read among progressives. A staunchly liberal journal, it was where the atheist and hawkish writer and Christopher Hitchens made his name before resigning as a columnist over the paper's dove-ish reaction to the attacks of September 11, 2001.

But it's a relatively small outfit. If the draft executive order was deliberately leaked by the administration – surely unlikely given that The Nation may not have contacts at the heart of the Trump inner circle – the journal would at first sight be an unlikely vessel.

Yet the move may have been tactical: government figures may have seen the opportunity to create liberal outrage both to underline to the Christian right what a gift it is they are receiving from the president, and to take the sting out of the progressive tail.

Further, by all accounts Trump's own tactics when it comes to making "deals" is to start with an extreme position and work back.

In other words, the leaked version may be harder than a more diluted order actually signed by the president in due course (the leaked draft is apparently currently doing the rounds among government officials).

Either way, the draft is at once shocking and, given what we now know about Trump's first weeks in office, unsurprising.