Hamas got 42% of the vote in 2006. At that point Israel tried to instigate a coup by Fatah, and Hamas seized power instead. That was the last election.
More than half of Gazans are under the age of 20, which mean that very few people alive in Gaza today could have voted for Hamas, and of that number 58% voted for someone else.
As far as the ahole's straw man arguments... Who fucking cares? He's a ruthless bigot. How do you argue with that?