Donald Trump supporter and bestselling author Ann Coulter warned Wednesday that any Republican in Congress who works with President Hillary Clinton would be seen as a "traitor."

Her comments were made in an interview with the Washington Examiner, soon after Rep. Steve King, R-Iowa, said that if Clinton were to win, he could see himself cutting a deal with her. "I've sat across the table with Hillary Clinton eye-to-eye, and when you're working outside of staff and outside of the press, she is somebody I can work with," he said in August.

But Coulter said it can't work that way.

"Any Republican who says he can work with Hillary Clinton is a traitor to the nation," she said. "It's finished."

Coulter, author of the new book In Trump We Trust: E Pluribus Awesome!, told the Examiner the U.S. and the GOP are both "over" if Clinton wins.

"They're whistling past the grave yard," she said. "It's not just the GOP, it's the country. It's over. It was fun while it lasted but the country is finished. She and [vice presidential nominee] Tim Kaine have vowed to push through amnesty. … You grant amnesty, there will be a rush for a border. … It's over. It's over if she's elected. … Go to a Cubs game and see how many people are in the stands because when you can't win, nobody cares anymore."

Coulter's new book is a full-throated endorsement of Trump, who she says is the country's last hope to preserve its culture and save the working class.

More of Coulter's interview with the Examiner to come soon.