WASHINGTON: Democrat Hillary Clinton and Republican Donald Trump are all but assured a US presidential showdown in November, but a third-party candidate — Libertarian Gary Johnson — will likely be on the ballot in all 50 states. Johnson, the former two-term governor of New Mexico, earned barely one percent of the vote in 2012 as standard-bearer for the Libertarian Party, which has yet to win a congressional race in its 45-year history and is hardly on the average American voter’s radar. But while Johnson is an unknown quantity compared to his headline-grabbing rivals, he sees the unprecedented chaos within the Republican Party and Clinton’s lingering image problems as his clearest-ever chance to break through with a frustrated electorate. “It really is” a golden opportunity, the 63-year-old Johnson told Agence France-Presse in an interview Monday (Tuesday in Manila) near the White House, insisting his campaign could pick up steam as voters seek a more palatable alternative to the provocative billionaire. Trump’s recent ascension as the GOP’s presumptive nominee has threatened to unravel the party. Several spooked Republican grandees have refused to back him in the general election, and there is a growing movement among conservatives to back an alternative candidate.