Democratic presidential nominee Hillary Clinton will be asked the first question at tonight's debate, having won a coin-toss earlier.
Scenes from Hofstra University on Monday.
Republican candidate Donald Trump's tweet before the debate:
Democratic candidate Hillary Clinton's tweet before the debate:
CNN interviewed former Democratic presidential candidate Bernie Sanders, who debated eventual nominee Hillary Clinton 10 times during the primary season, said Clinton "understands she's up against an entertainer," said what she has to do is "stay focused on the issues."