The precious achievements of democracy are of great importance to the people, which is why the people fight to preserve these democratic ideals.
Literal
Democracy's precious achievements [topic-は] people [for-にとって], extremely important thing [copula-である]. Therefore people [topic-は] this democracy's ideals [object-を] maintain for [ために] fight.
Two sentences joined by だから ('therefore, so'). にとって ('for X,' 'from X's perspective') marks whose viewpoint the value judgment applies to. ために with a verb is the purpose sense — 'in order to.' Note how Japanese uses だから to explicitly signal cause-effect between sentences, where English might rely on juxtaposition alone.