When you love something, you will try to protect it from harm even if that harm is being perpetuated by the thing itself.
A patriotic citizen is one who loves their country and so such a person would take actions that are aimed at protecting the country from harm regardless of whether the harm is external or internal.
When the harm is internal such as when a government wants to pass illegal or unjust laws, a patriot would protest these so that it does not happen and the country would be protected from the harm that would have happened.
