NEW YORK (Reuters) - U.S. stock index futures opened higher on Sunday ahead of a key U.S. presidential debate, which will be the first time the candidates face off after a video surfaced of Republican candidate Donald Trump making lewd comments about women.


The video has sparked turmoil in the campaign and led to Republicans calling for Trump to drop out of the race against Democrat Hillary Clinton.


S&P 500 e-minis <ESc1> were up 6 points, or 0.28 percent.


(Reporting by Caroline Valetkevitch; editing by Diane Craft)