The Pennsylvania-based judge has written two majority opinions reviewed by the Supreme Court.
Sykes wrote an opinion that ruled for employers in the fight over Obamacare's contraceptive mandate.
Moderator Chris Wallace began the debate by asking the candidates where they want the Supreme Court to take the country.
Federal law requires such comments to be "willful" for legal action to be taken.
"If she gets to pick her judges, nothing you can do folks," Trump said at a rally. "Although the Second Amendment people, maybe there is, I don't know."
No right is unlimited. A well-regulated militia does not include enemies of the state.
There is an easy solution to America's arguments about gun control, but the childish extremists on both sides need to leave the room.