Bill Clinton is deteriorating before our eyes.

The former president appeared in Tucson and Phoenix on Sunday and during an introduction by Mark Kelly, Clinton stood expressionless, seemingly chewing on his tongue with his mouth agape.

Kelly, and his wife, former Congresswoman Gabrielle Giffords, appeared with Clinton. As Kelly launched attacks against Republican front runner Donald Trump, Clinton stared off into the crowd. He looked at the floor, his mouth hanging open.

As the audience cheered for Kelly’s lines, Clinton stood motionless. Even Giffords smiled and nodded affectionately.

The campaign trail — and perhaps other factors — have clearly taken a toll on Clinton.

While campaigning in Iowa in January to rescue Hillary’s floundering presidential campaign, the former president’s hand could be seen trembling while he was making a point.

As he was explaining his wife’s rationale for invoking 9/11 to defend her ties to Wall Street, Clinton said, “She was making the point that the people devastated on 9/11 were people to her, not categories.”

Watch his left hand at the :30 mark:

In 2013, Clinton denied having Parkinson’s.

“I have a condition that sometimes you get with aging,” Clinton said at the time, the Huffington Post reported. “You may have noticed it; my hand has a little tremor when I’m tired and a lot of people do when they’re older.”

“The first time it happened, I had to go get myself checked to make sure I didn’t have Parkinson’s [disease],” he said.

He said his doctor claimed he didn’t though Clinton didn’t say what condition he has.