Complex sentence: Pence listened to the expression of concern about President-elect Donald Trump's upcoming administration, and later declared that he was not offended, but Trump demanded an apology for what he described on Twitter as the cast having "harassed" Pence.
Split into simpler sentences: Pence listened to the expression of concern about President-elect Donald Trump's upcoming administration and later expressed that he was not offended. However, Trump demanded an apology for what he described, on Twitter, as the cast having "harassed" Pence.