Highlights From the Libertarian Party Presidential Debate

— -- Libertarian presidential hopeful Gary Johnson faced off against his four main rivals on the debate stage on Saturday night, earning some of the night's loudest cheers and boos as he tried to sell his viability in the general election without alienating his party's more hardcore members.

JOHNSON DEBATE HIGHLIGHTS • When asked whether it was wrong for the United States to intervene in WWI? In WWII? Johnson's entire answer was "I don't know." This response got a lot of traction on Twitter as a major red flag for any Libertarian Party momentum.

• Gary Johnson also received boos for saying he would have signed the Civil Rights Act of 1964. (Libertarians object to Title 2 as a violation of the freedom of association.) This response also got traction on Twitter.

• Johnson was the only candidate who said he would require drivers to have licenses, citing possible dangers -- such as blind drivers. The crowd responded by booing loudly.

• Johnson: "If we legalized all drugs tomorrow, the world would be a much better place."

• "I'm not smart enough to say whether global warming is man-made,” said Johnson.

• On immigration: Johnson believes the U.S. should make it "as easy as possible" for people to get work visas. "We need to embrace immigration," said Johnson, adding immigrants "are the cream of the crop. They are not taking jobs that U.S. citizens want."

OTHER DEBATE HIGHLIGHTS • Libertarian candidate Austin Petersen, seen widely as Johnson's stiffest competition, said we don't need the government to build roads because "in the future, we’ll have jetpacks."

• Libertarian candidate Marc Feldman says he supports separate bathrooms -- one for people who wash their hands and one for those who don't.

• On global warming: "Whether or not global warming is real not, it’s not the government’s business to fight it,” said Petersen. Only John McAfee acknowledged man-made climate change.

• When asked how they would fund things like healthcare and the military, some of the candidates insisted they would depend on citizens' "voluntary contributions." "The military should be as big as can be on donations and bake sales," said Darryl Perry.

• On immigration: All Libertarian candidates who made the debate agree that the U.S. should have an open-borders policy. "I'd like to build a wall around Donald Trump and make Bernie Sanders pay for it," Petersen said. “If Donald Trump wins the election, we should revolt,” he added.

Delegates at the Libertarian convention in Orlando, Florida, will decide the nominee on Sunday. Most party insiders expect Johnson to win the presidential nod, but stiff competition from extreme wings of the party threatens to drag the voting out for multiple ballots.

Delegates will then vote separately on vice presidential nominations, where leaders here believe the race is more unpredictable. Johnson is pushing for former GOP Gov. Bill Weld, but some delegates are wary, saying he's not a true Libertarian.