A right-wing politician could win today's election for the Austrian presidency for the first time since the Second World War, as established parties that have dominated postwar politics watch from the sidelines.
Candidates backed by the dominant Social Democratic and politically central People's Party were eliminated in last month's first round, which means neither will become president for the first time since the end of the war.
That reflects deep disillusionment with the political status quo and their approach to the migrant crisis and other issues.
As voting got under way on today, the contest was too close to call between Norbert Hofer of the right-wing Eurosceptic Freedom Party and Greens Party politician Alexander Van der Bellen, who is running as an independent.
Both men drew clear lines between themselves and their rival as they went into Sunday's race.
At his final rally Friday, Van der Bellen said he was for "an open, Europe-friendly, Europe-conscious Austria" - an indirect contrast to what Hofer is offering.
Hofer, in turn, used his last pre-election gathering to deliver a message with anti-Muslim overtones.
"To those in Austria who go to war for the Islamic State, or rape women, I say to those people 'This is not your home'," he told a cheering crowd.
The elections are reverberating beyond Austria's borders, with a Hofer win being viewed by European parties of all political stripes as evidence of a further advance of populist Eurosceptic parties at the expense of the establishment.
In Austria, such a result could upend decades of business-as-usual politics, with both men serving notice they are not satisfied with the ceremonial role most predecessors have settled for.
Van der Bellen says he would not swear in a Freedom Party chancellor even if that party wins the next elections, scheduled within the next two years.
Hofer has threatened to dismiss Austria's government coalition of the Social Democrats and the People's Party if it fails to heed his repeated admonitions to do a better job - and is casting himself as the final arbiter of how the government is performing.
Political isolation for Austria could also be in the offing. Hofer as president is unlikely to be welcomed in most European capitals as governments there try to keep their populist Eurosceptic parties in check.
The Freedom Party's anti-Muslim campaigning also could result in governments in the Middle East avoiding him.
It would not be a first for Austria. President Kurt Waldheim, who was backed by the People's Party, was boycotted internationally decades ago after disclosures that he served in a German unit linked to atrocities in the Second World War.