There are 12 battleground states that deserve close attention as Democratic President Barack Obama and Republican Mitt Romney go head to head in Tuesday's historic election:
Of note: this year's major battlegrounds were swept by Obama in 2008.
-- THE BIG THREE --
OHIO (18 electoral votes)
Perhaps the crucial battleground, the state ravaged by industrial decline has trended Democratic after narrowly deciding the 2004 election for George W. Bush. But Romney has made a strong play for white, working-class voters. No Republican has claimed the White House without also winning Ohio.
RealClearPolitics.com polling average: Obama up 2.3 percent.
2008: Obama 51 percent, McCain 47 percent.
FLORIDA (29 electoral votes)
The biggest battleground of all, the Sunshine State had the starring role in the chaotic 2000 election and is now struggling to handle large numbers of early voters. State voter ID laws, which required a photo ID to vote, limited some early voting, but parts of the laws have been curtailed by federal courts.
RealClearPolitics.com polling average: Romney up 1.2 percent.
2008: Obama 51 percent, McCain 48 percent.
VIRGINIA (13 electoral votes)
2008 saw Virginia vote Democratic in a presidential election for the first time since 1964. The state's affluent and populous north next to Washington has turned blue, but a battle rages in the area around Norfolk, home to several large military bases. With military cuts looming, Romney may have an edge.
RealClearPolitics.com polling average: Romney up 0.5 percent.
2008: Obama 53 percent, McCain 46 percent.
-- THE CLOSE CALLS --
COLORADO (9 electoral votes)
Fueled by an influx of migrants from liberal California and elsewhere, the traditionally Republican mountain state has been trending Democratic. It voted for Obama in 2008, but the incumbent is finding it hard to hold together his winning coalition of women, youth and minorities here.
RealClearPolitics.com polling average: Obama up 0.5 percent.
2008 result: Barack Obama (D) 53 percent, John McCain (R) 45 percent.
NEW HAMPSHIRE (4 electoral votes)
With the race on a razor's edge, even tiny New Hampshire is getting extra love from both candidates wooing notoriously independent Granite State voters. Obama has campaigned here this year at least six times, and Romney eight.
RealClearPolitics.com polling average: Obama up 1.0 percent.
2008: Obama 54 percent, McCain 49 percent
IOWA: (6 electoral votes)
America's bread basket took Obama to its heart in 2008, when he won the Iowa caucuses to launch his Democratic juggernaut. Romney won this year's Republican contest -- until a recount declared Rick Santorum the winner. Romney is holding tough; its top newspaper just endorsed him, after backing Obama four years ago.
RealClearPolitics polling average: Obama up 1.3 percent.
2008: Obama 54 percent, McCain 45 percent.
NEVADA (6 electoral votes)
America's gambling capital was sucker-punched by high unemployment and the mortgage foreclosure crisis, and while jobless numbers have improved, they remain high. Obama has built big leads among Hispanic voters, but many Nevadans say he has not turned the economy around fast enough.
RealClearPolitics.com polling average: Obama up 2.4 percent.
2008: Obama 55 percent, McCain 43 percent.
NORTH CAROLINA (15 electoral votes)
Obama won this traditionally red southeastern state by just a few thousand votes in 2008. The president came out in support of gay marriage this year, while North Carolinians approved an amendment banning it. The issue simmers.
RealClearPolitics.com polling average: Romney up 3.8 percent
2008: Obama 50 percent, McCain 49.5 percent.
WISCONSIN (10 electoral votes)
Long in the blue column, Wisconsin is now in play, following a tumultuous recall battle over the Republican governor that forced the party to build up a vast political machine there. It's paying off. Obama's comfortable lead has shrunk. And Romney's running mate, Paul Ryan, is from the Badger State.
RealClearPolitics.com polling average: Obama up 4.0 points.
2008: Obama 56 percent, McCain 42 percent.
-- POTENTIAL SURPRISES --
PENNSYLVANIA (20 electoral votes)
Polls in this rust-belt state like next-door Ohio showed a safe bet for Obama six weeks ago, but the race has narrowed. Pennsylvania elected a Republican governor and Republican senator in 2010, and support for fracking for natural gas, which Romney advocates, is high in western Pennsylvania.
RealClearPolitics.com polling average: Obama up 4.6 percent.
2008: Obama 55 percent, McCain 44 percent.
MICHIGAN (16 electoral votes)
Nominally Romney's home state, Michigan hasn't voted for a Republican since 1988 and Obama is still the strong favorite here despite recent polls suggesting a tight race. Obama's bailout of Detroit auto giants GM and Chrysler, opposed by Romney but credited with saving the key industry in the state, could be the deciding factor.
RealClearPolitics.com polling average: Obama up 3.0 points.
2008: Obama 57 percent, McCain 41 percent
MINNESOTA (10 electoral votes)
One recent poll raised eyebrows when it showed Obama leading by only three points in the normally safe blue territory of Minnesota. There is little doubt the state has moved more to the center from the liberal left in recent election cycles but the "Land of 10,000 Lakes" hasn't voted for a Republican since the Richard Nixon landslide of 1972.
RealClearPolitics.com polling average: Obama up 5.0 points.
2008: Obama 54.1 percent, McCain 43.8 percent