Throughout the government shutdown battle, Reid repeatedly raged against "Tea Party anarchists" and "radical extremists" who were allegedly trying to take the "federal government and the economy hostage."
But Reid went a step further Thursday in an interview with the Huffington Post, ruthlessly mocking the freshman senator from Texas.
"He is a laughing stock to everybody but him," Reid said. "What has he accomplished other than raising some money for president?"
Reid said he wasn't alone among his Senate colleagues in criticizing Cruz.
"But you don't have to have Harry Reid criticizing him," he said. "Republicans criticized him. What do you think that vote was last night from Republicans? That was a message to Ted Cruz: 'What the hell are you doing?'"
The Senate majority leader suggested that Cruz had gone through life as an intellectual bully, but had finally met his match in the Senate where he lost.
"He is now in the Senate. People are as smart as he is. He can't talk down to anyone anymore. But he has still not accepted that in his own head," Reid said.
"He still thinks he's smarter than everybody else. He might be able to work a calculus problem better than I can. But he can't legislate better than I can," Reid said.
Republicans will be in deep political trouble, Reid suggested, if they continue to support Cruz after the latest shutdown battle.
"[I]f this man can get the nomination to be the Republican nominee for president, I pity the Republican Party," he said.