Oh, it's true that the country was narrowly divided. If the Democrats had only nominated a candidate who promised to raise taxes (like Mondale did in 1984), Bush would have probably gotten a higher percentage. Frankly, given the Clinton recession, the economic hit from 9/11, leadership shown in taking out Saddam which alienated some natural political allies, the rabid opposition by the international elites, the MSM, as well as an energized Democratic left (and a few carping conservatives), the President's increase in both absolute and percentage terms over the 2000 result was impressive.
Frankly, it would have been a lot higher is the President didn't single handedly blow life back into Kerry during the 1st debate. The Swifty's had dealt Kerry a death blow. Bush played Jesus to Kerry's Lazarus and brought him back to life.