Voters have one more formal opportunity to hear what presidential candidates Hillary Clinton and Donald Trump have to say, at the third and final presidential debate Wednesday night.

Anne Warfield will be eagerly observing what the candidates don't say.

For more than 25 years, the body-language expert has dissected the literal steps and verbal missteps, smiles and sneers, hand gestures and head shakes of political candidates vying for powerful seats in government.

This peculiar version of our body politic blew up in outrage on social media after Debate No. 2, where Trump's large frame and steely countenance hovered over Clinton from every camera angle for much of the evening.

But Warfield, CEO of Minneapolis-based Impression Management Professionals, said that far subtler gestures can carry more weight for voters, who generally "are very good at intuitively picking up on body language."

She said, "What they're trying to figure out is, 'Can I believe what this person is saying?' For a leader to be trusted, they really have to believe that he or she has our best interests at heart. Reading the body becomes important."

One of the best in body language, Warfield said, was former President Ronald Reagan. "He spoke slowly, and was really good at using humor to deflect tough things."

Former President George W. Bush wasn't as skilled in this department, she said. "When things were tough, he'd stick out his neck like a turtle. He didn't know how to create comfort."

While political fact checkers are blessedly working overtime this season, Warfield offers an assist with her own test of truth telling.

Readers: Grab your scorecard and a pencil.

Let's begin with lying. People who are lying will touch parts of their body, she said. They'll touch their eyes "to literally block sight out so they don't see who they are lying to." They'll touch the corner of their mouth "to literally block the words coming out."

They might lightly brush the underside of their nose.

And, yes, they'll scratch.

"They'll scratch the back of their neck, four or five times. If they think they're going to get caught, they'll feel a tingling sensation up their spine. They'll scratch to stop it."

Eyes can give away a lot of angst, too. Warfield recounts the first debate between President Obama and Republican challenger Mitt Romney. "Obama was blinking continuously, which suggested that he was nervous. Romney was crinkling the corners of his eyes, which also can be a sign of discomfort."

Hands and arms speak volumes, too. Also at the first Obama-Romney debate, Warfield recalled, Obama used fingers of both hands to hold a pen "to comfort himself." Not a good look. In the second debate, Obama had his fists closed tightly at one point, another sign of nerves.

Romney, in addition to crinkling his eyes, "got flustered at one point and dropped his shoulders down and placed his arms in front of him, which is a protective gesture."

Their respective handlers should have counseled them to clasp their hands together, which is considered "a reassuring gesture." Or better, palms open "as a show of honesty."

And what about stalking back and forth? Interestingly, Warfield didn't read anything insidious into Trump's constant appearance behind Clinton during Debate No. 2.

"I think he felt boxed in and that energy had to come out," she said. "I think he just has a hard time giving anyone the space they want. He wants to be in that space."

And that wasn't the only moment illuminating the candidates' height differential. Clinton "couldn't touch the floor" when she was seated, Warfield noted, "and that was socially awkward for her. That should have been checked out ahead of time so her stool had a resting spot for her feet."

Still, Warfield emphasizes that great leaders come in all heights and none should feel intimidated.

She noted that Clinton, when she was standing, took on a lot of husband Bill Clinton's winning gestures. "She'd walk right over to the individual, say their name, talk to them on an individual level."

"If you're shorter, don't try to be more forceful," she said. "The size of your aura is what people will feel."

So, candidates, look alive. Lean forward. Keep your head up or tilted to one side. Eyes and palms open. Shoulders back. Fingers out of your face. No constant blinking. No scratching. No photobombing.

Or you could simply speak the truth from the get-go.

"I would love to see the mic go dead after their two minutes were up," Warfield said, "so no one can hear what they said anymore."

gail.rosenblum@startribune.com 612-673-7350 • Twitter: @grosenblum