They have to live under their government. They will say and think what they want. The forerunners of the governing Ultra Nationalists, the Ukrainian Nationalists(OUN) under Stepan Bandera sided with the Nazis days after Hitler invaded the USSR in WW2, even forming their own volunteer Ukrainian division of the SS. The nationalists killed their fair share of fellow Ukrainians, Poles, Jews and Russians. They actually had their own little holocaust to purge people they feared would not support them. As many as half a million people.
Since then the ultra nationalists have called Stepan Bandera a hero and publically stated they want to purge all non ethnic Ukrainians from the country.
The people who live there are stubborn and have long memories. The Kiev government will have to perform actions to win them over, not fit the “Nazi” stereotype.
Do you realize the guy in charge of that party got 1.5% during the last elections ? It's Kremlin's propaganda shyt that “Banderists” are all over the place.