The Outcome of the Presidential Election of 2008 Would Have

The outcome of the presidential election of 2008 would have been less decisive if

A) the Democratic candidate, Barack Obama, wasn't African-American.
B) the Republican candidate, John McCain, had not been so old.
C) Sarah Palin had been selected as vice president on John McCain's ticket.
D) voter turnout had not been so low.
E) President Bush's popularity had not suffered from the recession and the war on terror.