VIENNA — When Sebastian Kurz became Austria’s youngest-ever chancellor two years ago, he made a pact to govern with the far right. He would in effect housebreak them, he suggested, checking their worst instincts.

In the 18 months that followed, Mr. Kurz, a conservative, had plenty of opportunity to try to do so: One official of the far-right Freedom Party that he had partnered with was found to use a fraternity songbook that celebrated the Holocaust. Another published a poem calling immigrants rats. A third put child refugees behind barbed wire and demanded that people who buy kosher meat register their names first.

Then in May, an old video surfaced showing the most senior government minister of the Freedom Party fantasizing about restricting press freedom and promising government contracts to a would-be investor close to President Vladimir V. Putin of Russia.

“Enough is enough,” Mr. Kurz declared and called for a snap election.

But that was then. On Sunday, Mr. Kurz is up for re-election. And all indications are that he will not only win again — but that he also may be open to another coalition with the same far-right Freedom Party.