Use 'chauvinist' in situations where someone shows unfair bias towards their group. During the debate, his chauvinist support for his own country ignored obvious facts.
Pro Tip 2/3
Offensive Term
'Chauvinist' is a negative word and can offend people if directed at them. Calling your teacher a chauvinist isn't appropriate if you disagree with them.
Pro Tip 3/3
Social Implications
Being aware that 'chauvinist' can have sexist implications, especially relating to male attitudes towards women. The manager's chauvinist joke about secretaries did not amuse his female colleagues.