Democratic US presidential nominee Hillary Clinton speaks as Republican US presidential nominee Donald Trump looks on during their presidential town hall debate at Washington University in St. Louis, Missouri, US, October 9, 2016. [Photo/Agencies]

Trump met just hours before the debate on Sunday with three women who had accused Bill Clinton of sexual misconduct and a fourth woman who was a victim in a rape case that Hillary Clinton participated in as a defense attorney. All four sat in the first row of the audience at the debate.

Before the debate, Trump had threatened he was going to attack Bill Clinton for his marital infidelities in response to criticism from Hillary Clinton that the Republican nominee is a misogynist who has a history of mistreating women.

Trump appeared with Paula Jones, who filed a sexual harassment suit against Bill Clinton in 1991, Juanita Broaddrick, who accused Bill Clinton of rape in 1978, and Kathleen Willey, a former White House aide who accused Bill Clinton of groping her in 1993.

None of the accusations was new. Bill Clinton was never charged in any of the cases, and he settled a sexual harassment suit with one of the women, Paula Jones, for $850,000 with no apology or admission of guilt.

Also at the event was Kathy Shelton, who was raped at the age of 12. Hillary Clinton, a practicing attorney at the time, defended the rapist who ultimately pleaded guilty to a reduced charge.

Clinton's campaign responded to Trump's pre-debate event by calling it a "stunt" and a "destructive race to the bottom."