Donald Trump during a Wednesday night rally invoked his 13-year-old son Barron Trump while attacking Democratic presidential candidate Sen. Elizabeth Warren…and then led the crowd in a chant of “lock her up” about Hillary Clinton.

“I could have Barron Trump go into Central Park and he’d get a crowd,” Trump said at the rally in Battle Creek, Mich. “He’d get a bigger crowd,” than Warren.

Trump attacked reports over Warren’s large crowd sizes and went on to tout the crowd sizes he’s had in recent weeks.

The president’s comments come after Republicans criticized a witness during the impeachment hearing for invoking Barron Trump during her testimony.

Stanford Law School professor Pamela Karlan said, “contrary to what President Trump has said, Article 2 does not give him the power to do anything he wants, and I’ll just give you one example that shows you the difference between him and a king, which is the Constitution says there can be no titles of nobility, so while the president can name his son Barron, he can’t make him a baron.”

Karlan later apologized after backlash from critics, including First Lady Melania Trump who said Karlan “should be ashamed [of] using a child [for her] biased public pandering.”

And then, a few minutes after Trump was formally impeached in the House of Representatives, Trump led his rally goers in their chant of “Lock her Up” after saying Hillary Clinton was too sickly to walk.

WATCH:

After Trump bashes Hillary Clinton for purportedly not being able to walk up stairs, his fans break out in "lock her up!" chants. Trump responds by suggesting that because of the IG report, it could still happen. pic.twitter.com/ZCnnvoxzeq

— Aaron Rupar (@atrupar) December 19, 2019