Donald Trump Jr. and Eric Trump on Father, Donald Trump: 'Tough' But 'Fair'

— -- Donald Trump, Jr. and Eric Trump acknowledged that their father and Republican presidential front-runner isn't a pushover, describing him as “tough” but “fair.”

When asked whether they were nervous for their father ahead of the Iowa Caucus, Eric said today on “Good Morning America”: "We’ve been going around the state and literally the energy is amazing, and the love we felt is incredible.”

“People have just embraced us so much, and it means so much when you see that kind of enthusiasm,” Donald Jr. added.

While Donald Trump’s campaign has inspired some, facing harsh criticism is new for the children of Donald Trump, and Eric admits it isn’t always easy.

“It’s hard. You always want to defend your father. He’s our best friend and we love him to death,” Eric Trump told ABC News’ George Stephanopoulus and Robin Roberts. “But if you’re running for commander-in-chief of the free world, you better have thick skin. You have to get used to that. That’s just the nature of politics.”

In spite of that, both children agree that their father is "ready."

“He’s doing it and doing it well,” Donald Jr said.

In the latest Des Moines Register-Bloomberg Politics poll, the real estate mogul holds a 5-point lead over main GOP rival, Ted Cruz.