CANBERRA, Australia -- Bill Shorten, the man most likely to become Australia's prime minister in elections on Saturday, has the solid support of his center-left Labor Party behind him. But the Australian public isn't so sure.
Shorten first found the public spotlight as a miners' union boss in 2006 when the world media was transfixed on a gold mine collapse drama that ended with the rescue of two miners who had been trapped underground for two weeks. He is still contending with accolades and condemnation for saying three years ago that some of then-presumptive Republican presidential nominee Donald Trump's views were "barking mad."
While the party he leads is popular, Australians have not warmed to the idea of Shorten becoming their next prime minister.
Even though the ruling conservative Liberal Party-led coalition has lagged behind Labor in opinion polls for the past two years, Shorten has been rated a less popular leader than Prime Minister Scott Morrison and the prime minister Morrison replaced in a Liberal Party revolt nine months ago, Malcolm Turnbull.
But despite an apparent lack of charisma, most experts expect that the 52-year-old Shorten will lead his party into power for the first time in six years.
Shorten became opposition leader in 2013 under Labor's new democratized voting system that for the first time gave more than 30,000 grass-roots party members the same say as Labor lawmakers on the choice of their leader in Parliament. Previously the decision had been lawmakers' alone.
Most lawmakers backed Shorten, who had long been a party power broker. Most of the unelected party members opted for his left-wing rival, Anthony Albanese.
While Shorten narrowly won the day and the party has appeared united under his leadership since, his lack of public appeal has seemed a vulnerability.
Morrison has cast the election as a simple choice between him and Shorten as prime minister. A government-aligned minor party, the United Australia Party, has dubbed Shorten "Shifty" in campaign advertising.
Labor advertising emphasizes its leadership team, highlighting Albanese, as well as high-profile women Tanya Plibersek and Penny Wong.
The Labor ads also highlight the party's higher proportion of female lawmakers and its claim to greater unity than the conservatives, who remain bitterly divided over rivalries that resulted in the Liberal Party removing its own prime minister in 2015 and again last year.
Nick Economou, a Monash University political analyst, disregards opinion polls about the popularity of party leaders, saying the parties' support is what counts.
An extraordinary feature of Australian politics is that voting is compulsory. In the absence of inspiring leaders, voters turn out in large numbers to avoid a 20 Australian dollar ($14) fine.
"It's not about the popularity of the leader, unless of course the leader is such a stinker that it can affect the vote," Economou said.
"People underestimate Shorten, but all the tests that have been set for him so far have been passed," he added.
Those tests include leading his party close to victory in 2016 elections and retaining Labor seats in five by-elections since then.
Opposition leaders are often unpopular at the federal and state levels because of the nature of the role, which is often described as the hardest job in politics. Opposition leaders are seen as negative and obstructionist.
Trump seemed a long shot for the White House when Shorten criticized him in a radio interview on May 27, 2016, during Australia's last election campaign.
"I think Donald Trump's views are just barking mad on some issues," Shorten said.
"America's a great friend of Australia; whoever they dish up we'll work with, but wow, Trump's sort of — it's sort of the ultimate victory of celebrity politics," he added.
Then-Prime Minister Turnbull accused Shorten of potentially offending Australia's most important strategic ally by breaking a long-standing Australian convention of avoiding taking sides in U.S. political contests.
Shorten has long stopped publicly criticizing Trump.
"How will I deal with Donald Trump? ... Professionally and politely," he told reporters last week. "Whatever the American democratic system elects, we'll work with them."
Turnbull was replaced by Morrison, then a senior minister, in a revolt by ruling Liberal Party lawmakers at least partly because of the government's poor performance in opinion polls.
The government has also portrayed Shorten as being reckless with policies that would harm Australia's economy.
Energy policy is as contentious as any in Australia, the world's biggest exporter of coal and liquid natural gas. Labor wants to cut Australia's greenhouse gas emissions by 45 percent below 2005 levels by 2030. Australia committed in the Paris Agreement on climate change to reduce its emissions by 26 or 28 percent by 2030.
Shorten was first elected to Parliament in the same 2007 elections that swept Labor to power for the first time in more than 11 years. Morrison, who is a year and one day younger than Shorten, entered Parliament in the same election.
Shorten has deep labor union roots. His father was a waterside laborer and union official, and his mother was a lawyer and university academic. He became involved in Labor politics as a student and was soon touted as a potential prime minister. He worked for less than two years as a lawyer before becoming a union official.
His regular news conferences on behalf of the powerful Australian Workers' Union at the Beaconsfield gold mine collapse in Tasmania state that killed one miner and left two trapped in 2006 created a national profile before he entered Parliament the following year.
But as a party power broker, Shorten played a key role in deposing two prime ministers through internal government leadership ballots in the face of poor opinion polling during Labor's chaotic six years in office.
His history of fickle loyalty in ousting leaders he once supported has been raised by his enemies as good reason for voters not to trust him.