NEW YORK - A payment meant to silence a porn star in the days before Donald Trump’s stunning election victory in 2016 may now result in his being the first US former president ever to be indicted.

How did it come to this? How is Trump defending himself, and what risks does he face?

Here are some key elements of the case:

Hush money payment

At a key point in the 2016 presidential campaign, intense negotiations were under way behind the scenes to prevent the leak of embarrassing, and potentially crippling, allegations against the Republican candidate.

In August, The National Enquirer, an American tabloid whose owner is a Trump ally, paid US$150,000 to a model, Karen McDougal, for the rights to her story about a relationship she claimed to have had with the billionaire. The objective was to prevent any word of her allegations from getting out – a technique known as “catch and kill” in the United States, where confidentiality clauses are common.

Meantime, Stephanie Clifford – a pornographic film actress who goes by the name of Stormy Daniels – was also trying to cash in on a relationship she says she had with Trump in 2006, a year after he married his current wife, Melania.

The tabloid put her in touch with Michael Cohen, one of Mr Trump’s personal lawyers. Late in the 2016 campaign, Mr Cohen, whose fierce loyalty to Mr Trump had earned him the nickname of “the Pitbull,” arranged a payment of US$130,000 to Ms Daniels in exchange for her pledge of confidentiality.

The payment was revealed by the Wall Street Journal in January 2018. Mr Cohen and Mr Trump dismissed the report, and the then-president repeatedly denied having had a relationship with Ms Daniels.

Undeclared campaign gift?

Mr Cohen, who was already entangled in