2016-08-02-RichardHanna.jpg

U.S. Rep. Richard Hanna, R-Barneveld, says he will vote for Democrat Hillary Clinton for president. Hanna said the GOP nominee, Donald Trump, is unfit to serve. The three-term congressman is shown speaking July 18, 2016, with students from the National Institute of Science and Technology's Summer Undergraduate Research Fellowship.

(Provided photo)

WASHINGTON, D.C. -- U.S. Rep. Richard Hanna, a three-term Republican, said Tuesday he will vote for Hillary Clinton for president because Donald Trump is "unfit to serve our party and cannot lead this country."

Hanna becomes the first Republican member of Congress to publicly declare he will vote for Clinton in November.

Other GOP members of Congress have refused to endorse Trump, but until now none had promised to vote for his Democratic opponent.

Hanna announced his decision Tuesday morning in an op-ed and interview exclusive to Syracuse.com. The retiring congressman previously said he could never support Trump, but he had stopped short of backing Clinton.

Now Hanna's decision could give political cover in the coming weeks to other like-minded GOP members of Congress who have criticized Trump, but have not said whether they would support Clinton.

Hanna, who represents an eight-county district in Upstate New York, said in an interview that he considered giving his support to Clinton for several months. He decided to take action this week after watching Trump criticize the Muslim American parents of a U.S. Army captain killed in Iraq, he said.

Trump clashed with Khizr and Ghazala Khan after they appeared on stage at the Democratic National Convention last week. Trump roughly dismissed the couple's criticism, and suggested Ghazala Khan was prevented from speaking at the convention because of her Muslim faith.

Hanna said it's unthinkable that anyone would criticize Gold Star parents.

"I saw that and felt incensed," Hanna said in an interview. "I was stunned by the callousness of his comments."

He added, "I think Trump is a national embarrassment. Is he really the guy you want to have the nuclear codes?"

Hanna, 65, of Barneveld in Oneida County, announced plans in December to retire when his term expires at the end of the year. But even before the announcement, he had developed a reputation for his independence and criticism of the most conservative of the Republican House caucus.

He has frequently split with his GOP colleagues on social issues such as abortion and same-sex marriage, and is among only 13 Republican House members to acknowledge that humans have contributed to climate change.

In his op-ed Tuesday, Hanna said he finds Trump "deeply flawed in endless ways" and "unrepentant in all things" including the use of bankruptcy laws to avoid the consequences of his choices.

"In his latest foray of insults, Mr. Trump has attacked the parents of a slain U.S. soldier," Hanna wrote. "Where do we draw the line? I thought it would have been when he alleged that U.S. Sen. John McCain was not a war hero because he was caught. Or the countless other insults he's proudly lobbed from behind the Republican presidential podium. For me, it is not enough to simply denounce his comments: He is unfit to serve our party and cannot lead this country."

Asked if he was concerned about potential backlash from his fellow Republicans in Congress, Hanna said, "I can't look back in my life when I leave this job and know that I didn't speak the truth when it was important to do so."

Contact Mark Weiner anytime: Email | Twitter | Facebook | 571-970-3751