LEE’S SUMMIT, Mo. — Lisa Ballenger didn’t volunteer for Hillary Clinton in 2016. She didn’t think she needed her help.

But on a hot and sunny Saturday here late last month, Ballenger made sure to go to a packed campaign office in a plaza, where Sen. Claire McCaskill rallied volunteers about to go knocking on doors for her.

“You know what my secret is?” said McCaskill, who is seeking a third term in November. “We’re going to turn out in bigger numbers than we’ve ever turned out!”

Ballenger, a 47-year-old director of a sign language interpreting agency, said President Donald Trump’s victory in 2016 motivated her to actively campaign for McCaskill.

“We need to show our friends and neighbors that we are showing up for her,” she said.