Trump biographer David Cay Johnston warns 'we're watching the Republican Party die right before our eyes'

Pulitzer Prize-winning investigative journalist David Cay Johnston got to know President Donald Trump as a business and economic reporter in New York. He's now become the definitive expert and biographer on the truth behind the Republican leader.

In an interview with SiriusXM Radio host Dean Obeidallah, Johnston explained that the president has no real sense of shame.

"Donald Trump is a man utterly without conscience or regard for other people," Johnston said. Sadly, he said that the sentiment even extends to Trump's own family.

"When you and I step on an ant on the sidewalk walking down the street we don't give it any thought," he continued. "Sorry for the ant, you're in the wrong place. It's not even a thought we stop and worry about. Donald Trump steps on people and it doesn't impinge on him in any way. This is the man that publicly humiliated the mother of his three oldest children and they didn't speak to him for years."

He noted that the children didn't speak to him until they got into the job market and realized they couldn't make as much money at a normal job, but they could working for their father.

In a second segment, they discussed the election results in Florida Tuesday and the impact Trump had on Rep. Ron DeSantis' (R-FL) race. Johnston explained the way in which Trump is taking down the Republican Party the same way he takes down everything.

"We are seeing the Republican party die right before our eyes," he said. "And become the cult of Trump."

He went on to nail so-called "principled Republicans" cowards for being more afraid of keeping their job that they don't even do their job.

"When I say that to you, one of the things I think about is I grew up under not terrific circumstances because my father was 100 percent disabled veteran of World War II," Johnston said. "My dad was willing to go die for this country and suffered terrible consequences and died prematurely because of it. And these guys are afraid to speak the truth because they'll get voted out of office? I mean, that's just so lacking in character and honor that I can't respect those people."

Listen to the two clips below: