"Barack Obama calling this judge a moderate doesn't make him a moderate," he said on "Fox News Sunday."
"This judge would move the court dramatically to the left."
McConnell said Garland is supported by MoveOn.org. He added that he can't imagine a Republican majority in the Senate in a lame-duck session would want to confirm a nominee who is opposed by the National Rifle Association and the National Federation of Independent Business.
"I can't imagine that a Republican majority Senate ... would want to confirm a judge that would move the court dramatically to the left," he said. 
McConnell also avoided a question about whether his ranks are breaking since some Republicans have agreed to meet with Garland.
"I think what we need to focus on is the principle," he said.
"We think the important principle in the middle of this presidential election which is raging, is that the American people need to weigh in and decide who's going to make this decision, not this lame-duck president on the way out the door, but the next president, next year."