Complex sentence: McCain surged ahead of Obama in the national polls following the nominationm but amid a financial crisis and a serious economic downturn, McCain and Palin went on to lose the election to Democrats Barack Obama and running mate Joe Biden.
Split into simpler sentences: McCain surged ahead of Obama in the national polls following the nomination. Amid a financial crisis and a serious economic downturn, however, McCain and Palin went on to lose the election to Democrats Barack Obama and running mate Joe Biden.