"As clucks of disapproval about Americans' political apathy have grown louder in recent years many historians have looked for contrast to the decades before the Civil War as a time when Americans were enthusiastically engaged in politics."
I am non-native speaker, and I am confused with the interpretation of the sentence "look for contrast to the decades". "look for contrast to something" implies that historians do not want to look for something (I think that is why historians look for contrasts to decades instead of "look for decades"). That is, historians do not want enthusiastic politics. If it is the case, the sentence doesn't make sense because it first says "there is disapproval about political apathy", and it follows that "historians do not look for enthusiastic politics".
Please give some any comment.
Thank you in advance!