(NewsNation) — They’re both old, so it’s no surprise that both President Joe Biden and former President Donald Trump will have bad days, according to a Democratic governor who is also a physician.

“The president was exhausted, no question,” said Josh Green, the governor of Hawaii. “He did not do well in that debate. But he did do much better when he was explaining foreign policy to the rest of the nation. He was quite sharp,” said Green, referring to Biden’s news conference Thursday.

“An 81-year-old gentleman is going to have moments where they skip a word, or they feel exhausted. That was the case when we had Ronald Reagan as president. And he went on to two terms … viewed as very successful by many.”

Green told “The Hill on NewsNation” that, despite skipping a word here and there, or stuttering, “cognitively, he is quite able to put major complex policies together.”

Green, one of the Democratic governors who met with Biden at the White House following the debate with former President Donald Trump, said the two men share something that neither can deny.

“These two gentlemen are old. Is that a surprise? No. It doesn’t take a physician to tell you that.”

But Green warned that, even though both men are old, they are very different.

“If you look ‘under the hood’ of each, you see different things: perhaps some fatigue on President Biden’s part, and a pathologic personality, unfortunately, on Mr. Trump’s part. And that’s really what’s quite scary to people. That’s why this election is extremely close still.”