Former US President Donald Trump, who is hoping to win a second term, was widely booed during his speech at the Libertarian convention.
Some audience members applauded and cheered as Mr Trump took to the stage, but soon a choir of jeers took over the room.
Mr Trump hit back at his critics saying: "Maybe you don't want to win... keep getting your 3% every four years."
The Libertarian Party puts individual rights and free markets at the core of its beliefs.
Their 2016 presidential candidate, Gary Johnson, won about 3% of the national vote.