The Libertarian party nominated a little-known political activist to be their presidential nominee on Sunday, rejecting an overture from President Trump to unify against Joe Biden's "regime."

38-year-old Chase Oliver, a former U.S. Senate candidate from Georgia, won the nomination after several rounds of voting.

Libertarians pick a nominee

Oliver's victory was a rebuke of the party's right-wing Mises Caucus, which invited Trump to speak at the convention. The caucus' candidate, Michael Rectenwald, lost in the sixth round after leading in the first five.

Oliver cleared the 50% threshold needed to win after striking a deal with another candidate, Mike ter Maat, who will be Oliver's running mate.

Trump had sought common ground with the small-government, anti-war party in a speech at its convention on Saturday. He was met with a mix of cheers and jeers as he invoked his multiple indictments to cast himself as a martyr for freedom against the "tyrant" Biden.

"If Joe Biden gets back in, there will be no more liberty for anyone in our country. Combine with us in a partnership," Trump said.

Trump also touted his record of not starting any new wars and pledged to place a libertarian in his Cabinet. But these appeals fell short, and Trump received only six write-in votes during the first round on Sunday.

"Keep getting your 3%"

Trump said he was barred from competing because he is the presumptive Republican nominee for president.

"The reason I didn't file paperwork for the Libertarian Nomination, which I would have absolutely gotten if I wanted it (as everyone could tell by the enthusiasm of the Crowd last night!), was the fact that, as the Republican Nominee, I am not allowed to have the Nomination of another Party," he wrote.

Independent candidate Robert F. Kennedy Jr. - whose campaign has focused on government overreach during the COVID pandemic - also spoke at the convention over the weekend. He received 19 votes in the first round.

Oliver previously ran for the U.S. House and Senate in Georgia. He holds some positions that conservatives would consider left-wing, including tolerance for abortion, open borders, and "drag queen story hour."

He was dismissive of Trump's speech, saying, "I don't like having a war criminal on this stage."

The Libertarian party is a tangential player in American politics, known more for ideological squabbling than winning elections, something Trump noted in jest during his speech at the convention.

"Maybe you don't want to win... keep getting your 3% every four years," he said, while asking for the party's endorsement.