Donald Trump’s refusal to say whether he would accept the outcome of next month’s US presidential election if he were to lose is unprecedented and chilling, legal experts have said. But although the failure by a major party nominee to concede defeat on election night would throw American democracy into uncharted territory, from a legal standpoint, it would hardly make a difference, experts from across the political spectrum said. “Frankly, under our system, it is irrelevant whether the loser concedes or not,” said James Bopp, the conservative constitutional lawyer. “The vote of the electoral college is conclusive.” … Trump’s reticence does not appear to be shared by those closest to him. Just hours before the debate, Trump’s running mate Mike Pence, his campaign manager Kellyanne Conway and his daughter, Ivanka Trump, all insisted that the campaign would accept the result of the election.
Under the electoral college system, Americans do not directly elect their president. They choose a slate of electors who pledge to vote for a certain presidential ticket. A candidate needs to win 270 electoral votes to win the election.
Though a winner is usually projected on election night, the official vote of the electoral college does not take place until some weeks later.
In those intervening weeks before the electoral college vote, Trump could mount a legal challenge to contest the result or demand a recount under certain circumstances but unless the vote margin is slim his chances of his case being successful are low.