Complex sentence: At the end of the month, as Hubert Humphrey was narrowly selected over Eugene McCarthy as the Democratic presidential nominee at a protest filled convention, commentators opined that the split party and lack of "law and order," placed Nixon in good position.
Split into simpler sentences: At the end of the month, Hubert Humphrey narrowly won Democratic presidential nominee over McCarthy at a protest filled convention. Pundits argued that the split party and lack of "law and order" at the convention placed Nixon in a good position.