Captain John James flew Apache helicopters on multiple tours of Iraq during an eight-year Army career.
Now he faces a battle to become Michigan's first Republican senator since 1994.
The 39-year-old is running in the same state that could decide whether Donald Trump gets another four years or is unseated by Joe Biden.
In 2016, Mr Trump won Michigan by less than 11,000 votes and it looks set to become a bloody battleground, particularly if there is a legal challenge over the result.
On Wednesday, he was leading over Democrat incumbent Gary Peters with 52 per cent of the vote, but with hundreds of thousands of postal votes still in play.
The former pilot, who was honourably discharged and went on to run his family's shipping business, has previously spoken of being racially profiled by police.
He said he was pulled over on multiple occasions by police for no apparent reason – an issue that has caused deep divisions between communities and law enforcement in major American cities.
"I didn't see the George Floyd video – I felt it," he said in an interview with The New York Times in July, referring to the black man whose neck was knelt on by a Minneapolis police officer, causing his death.
He spoke of an incident in the past when he and the woman who is now his wife were approached by police, with guns drawn, as they sat in their car at an upscale mall in Detroit.
He suggested had his wife, who is white, not been with him to de-escalate the situation, he does not "know what would have happened".
But critics have noted Capt James' near-refusal to criticise incumbent President Donald Trump, who has shared racist videos on his Twitter account and whom polls show is mistrusted when it comes to handling race relations.
That is despite his status as the Republicans' only black candidate running for the Senate.
Although he denounced Floyd's killing as a "cowardly act of evil", he said the rioting that broke out during protests was "criminal", which caused anger among protesters.
Capt James appeared in campaign videos flaunting his US Army Ranger training – but shied away from commenting on claims that Mr Trump called servicemen and women who died in wars 'losers' and 'suckers'.
In an interview, The New York Times pressed the veteran on several points including the renaming of military bases named after Confederate commanders.
He repeated Mr Trump's warnings not to "rewrite history".
He has also pointed out that phrases such as "Black lives matter" are lost on many white, conservative and rural voters, but he hoped he can be a “cultural translator” between black Americans in mostly white communities.
Capt James stressed that he stood for “stability, unity in leadership".
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