IRAQ: Most Americans are unhappy with the Bush administration's conduct of the war but Republicans will argue that Democrats would endanger America by pulling US forces out too soon.
TERRORISM: National security helped Republicans to win in 2002 and 2004 but Democrats claim that, five years after 9/11, the "war on terror" has damaged civil liberties and failed to make America safer.
IMMIGRATION: Deadlock between the Senate and House of Representatives has blocked immigration reform and Democrats hope voters will blame the Republicans, who control Congress.
ECONOMY: Despite sustained economic growth, US wages have been stagnant, fuel prices have soared and most Americans believe the economy is not doing well.