Budapest - Hungary's strongman premier Viktor Orban, running for re-election on Sunday, is a poster boy for nationalists worldwide, the self-styled defender of Christian Europe and scourge of the "globalist elite".

After half a lifetime in the political spotlight, Orban has concentrated a huge amount of power in his hands, and now rails against the "poison" of immigration and says he favours an "illiberal" version of democracy.

For this he has won plaudits from populists elsewhere. Steve Bannon, US President Donald Trump's former chief strategist, has called Orban a "hero" and "the most significant guy on the scene right now".

But to his detractors Orban, 54, is a xenophobic demagogue aping Russian President Vladimir Putin by eroding democracy in the EU member state, while corruption flourishes and public services rot.

At 26 as a law student in Budapest, the football-mad country boy became a household name in Hungary in the dying days of communism in 1989 with a stirring speech telling Soviet forces to go home.

Co-founding the Alliance of Young Democrats party (Fidesz), the ambitious Orban was one of "new" Europe's brightest stars, becoming an MP in newly democratic and optimistic Hungary in 1990.

Soon, however, he shed his image as a radical youth and began moulding Fidesz into a new force of the centre-right keen on family and Christian values.

It paid off in spades, and with the charismatic Orban developing a rare knack for connecting with ordinary voters he duly became prime minister in 1998, aged just 35.

- Tearing it up -

His first period in office was rocky, however, and Orban lost to the Socialists in 2002 and again in 2006 before bouncing back in 2010 -- and with a vengeance.

This time armed with a two-thirds majority in parliament, Orban set about implementing a root-and-branch reform of Hungarian state institutions and writing a brand new constitution.

Critics at home and abroad, including in Brussels and Washington, worried that the sweeping changes undermined the independence of the judiciary, muzzled the press and rigged the electoral system.

Orban maintains that he was repairing years of Socialist mess, while his unorthodox economic policies like special "crisis" taxes on foreign companies helped Hungary balance the books.

He was re-elected in 2014 and Europe's migrant crisis the following year saw Orban morph into a lightning rod for opposition to German Chancellor Angela Merkel's "open-door" refugee policy.

As hundreds of thousands of people streamed through Hungary bound for western Europe, and with Budapest train stations resembling squalid refugee camps, Orban erected a razor-wire fence on Hungary's border with Serbia.

Illegal immigration -- a "Trojan horse for terrorism" -- was made punishable by lengthy jail terms. It was Hungary's duty, he said, to defend the outer borders of the European Union.

- Soros in his sights -

Orban's strident stance has turned Hungary, along with Poland's like-minded government which has also raised concerns with its own reforms, into a headache for Brussels and the rest of the EU.

But Orban is now the darling of nationalists, from Bannon to France's Marine Le Pen to Geert Wilders of the Netherlands. White supremacists have wanted to settle in "racially pure" Hungary.

Orban's latest target meanwhile is George Soros, the Hungarian-born US financier and philanthropist who helped Fidesz get off the ground and whose scholarship funded Orban's time at Oxford in 1989.

Orban has plastered Hungary with billboards urging resistance to the alleged "Soros plan" of destroying Europe with immigration and the civil society groups that the 87-year-old funds.

For critics, the imagery and language used in this campaign against the Jewish Soros have more than a whiff of anti-Semitism.

Hungary’s enemies, Orban said in a recent speech "are not national, but international. They do not believe in work, but speculate with money. They have no homeland, but feel that the whole world is theirs."

- Million-dollar question -

Whether Orban is an opportunist or a visionary is unclear, Andras Schweitzer, senior lecturer at Eotvos Lorand University, told AFP.

"It's the million dollar question," Schweitzer said. "Either way lots of people who have met him, including if they don't support him, notice his ability to understand things very quickly."

Hungary's opposition has long appeared powerless, crushed and divided by the Fidesz juggernaut, and polls indicate Orban is firmly on course for a record third consecutive term in office.

However, a shock by-election defeat in February for Fidesz when all opposition parties united behind one candidate has raised hopes among Orban's opponents that he is vulnerable after all.

That result, analysts said, revealed deep frustration that for all the talk about Soros, immigration, and rosy economic headline numbers, corruption is widespread and public services are a mess.

By Simon Sturdee