As for gerrymandering, that only affects the House races, nothing else. The President isn't affected by that, only by the archaic and undemocratic Electoral College and the way state borders are drawn. The Senate is similar. The GOP swept all three.
It looks like the voter turnout was pretty average. Going back to 1972, the turnout numbers are similar: https://en.wikipedia.org/wiki/Voter_turnout_in_the_United_St...
Thank you for the reminder about the limitations of gerrymandering!
Senate is 52-48 which doesn't seem like a sweep. This includes two independents which caucus with the Democrats. I think the Democrats actually picked up two seats, which doesn't seem like a sweep either. Also, in your previous comment, you said the GOP won some seats. Which seats were these?
Donald Trump had a victory margin in the bottom 10 of historical elections: https://en.wikipedia.org/wiki/List_of_United_States_presiden...
http://www.electproject.org/2008g http://www.electproject.org/2016g
I will also note that the poster you're replying to references gerrymandering as one of the causes of the election results not matching the votes; neither of your statements directly refute that.
http://www.npr.org/2016/06/15/482150951/understanding-congre...