Trump and Clinton will answer questions “town hall-style” allowing audience members to directly question the candidates, a more personal format than the moderator-driven first round on September 26.
Trump's poll numbers across the country have generally fallen since the previous debate, which attracted a record 84 million views.
The Republican has simultaneously claimed to have won the debate while also blaming the Commission on Presidential Debates for giving him a faulty microphone.
Nationally, Clinton leads Trump by an average of 4.5 percentage points, according to a Real Clear Politics poll released on Friday.
In Ohio, another key state, Clinton and Trump are statistically tied at 44 and 42 percent, according to a Monmouth University poll released on Wednesday. Clinton was ahead by four points in August.
On Thursday, the Detroit Free Press/WXYZ-TV poll revealed that Clinton reclaimed the lead over Trump in Michigan and is leading him 43-32 percent. One month ago Trump had narrowed the gap with Clinton to three percentage points.
Polls continue to report that both candidates have among the highest negative perceptions among US voters in general.
The more casual debate format could be an opportunity for Trump to win undecided voters. He is also likely to benefit from his running mate Mike Pence’s success at the first vice presidential debate last week.