Focus on key states in US election 

Tuesday's US presidential election will be decided in about a dozen battleground states where most opinion polls show Democrat Barack Obama ahead of Republican rival John McCain.

Obama, who leads in every national opinion poll, is ahead in all the states won by Democrat John Kerry in 2004 as well as in several states won by Republican President George Bush, recent polls show.

The victor needs 270 electoral votes to win the Electoral College and capture the White House.

The president is determined not by the most votes nationally but by a majority of the Electoral College, which has 538 members allotted to all 50 states and the District of Columbia in proportion to their representation in Congress.

Each state, except Maine and Nebraska, awards its votes to the candidate who gets the most votes in the state. Maine and Nebraska split them by congressional district.

Here are some battleground states with their electoral vote totals, 2004 results and recent details about the contests in each state.

Colorado
Nine electoral votes. Bush beat Kerry 52% to 47% in the state in 2004, but since then, Democrats have won the state legislature and governor's office. The two latest polls put Obama up by 7 and 5 points respectively.

Florida
Twenty-seven electoral votes. Bush beat Kerry 52% to 47% in a state known for the disputed result that decided the 2000 election. Florida is a classic swing state with many older voters who could favor McCain along with Jewish voters who are normally Democratic but have been wary of Obama. The most recent polls give Obama a lead of between 2 points and 7 points.

Indiana
Eleven electoral votes. Bush beat Kerry by 20 points in 2004 in a state that last voted for a Democrat in 1964. But it borders Obama's home state of Illinois and he has poured resources into his Indiana campaign after finishing a strong second to Senator Hillary Clinton in the May Democratic primary. The race remains a toss up, with the two most recent polls showing the state a dead heat.

Missouri
Eleven electoral votes. Bush beat Kerry 53% to 46% in 2004 in a classic battleground with a mix of cities and conservative rural areas. In the two most recent polls, the race was dead even or McCain was ahead by one point.

New Hampshire
Four electoral votes. Kerry beat Bush by 1 point in 2004. McCain's history of big primary wins in New Hampshire in 2000 and this year gives him hope he can take the state in November. Democrats captured both the state's seats in Congress and gained control of the state Legislature in 2006 in an anti-Republican wave on which Obama hopes to capitalize. All 5 of the most recent polls show Obama ahead with a lead ranging from 7 to 15 points.

New Mexico
Five electoral votes. Bush beat Kerry by fewer than 6,000 votes in 2004. As the senator from neighboring Arizona, McCain is familiar to many New Mexico voters, but he will have to battle Obama for the growing bloc of Hispanics, who make up more than 40% of the state's population. The most recent poll shows Obama ahead by 10 points.

Nevada
Five electoral votes. Bush beat Kerry by 20,000 votes in 2004 in a state won by Republicans in eight of the past 10 presidential elections. As in New Mexico, the burgeoning Hispanic population will be crucial - it now makes up nearly a quarter of Nevada's residents. Two recent polls gave Obama a 4-point lead, and another had his advantage at 5 points.

North Carolina
Fifteen electoral votes. Bush beat Kerry by 12 points in 2004, even though the Democratic vice presidential nominee, John Edwards, was from the state. More than one-fifth of the population is black and an influx of transplants to high-tech urban areas have given Obama a chance. One recent poll showed the race even, another gave McCain a 3-point edge and another gave Obama a 2-point edge.

Ohio
Twenty electoral votes. Bush beat Kerry by about 120,000 votes in the state that ultimately decided the 2004 race. No Republican has won the White House without Ohio, and McCain will have a hard time piecing together a win without the state. One new poll gave McCain a 2-point lead, while others have given Obama a 4-point to 6-point edge.

Pennsylvania
Twenty-one electoral votes. Kerry beat Bush 51 percent to 48 percent in 2004, but Pennsylvania is one of a handful of states won by Kerry where McCain's camp had seen a chance to reverse the result. The most recent polls give Obama a 4-point to 6-point edge.

Virginia
Thirteen electoral votes. Bush won fairly easily by 9 points in 2004 in a state that has not gone Democratic in a presidential election since 1964. But Virginia has trended toward Democrats in recent state elections amid dramatic growth in the Democratic-leaning northern suburbs of Washington, DC Four polls in the last four days have given Obama a lead of between 3 points and 9 points.

Wisconsin
Ten electoral votes. Kerry won by 11,000 votes out of more than 3 million in 2004, but Obama has held a lead for months in a state where he crushed Hillary Clinton in a February Democratic primary showdown. The three most recent polls show Obama ahead by 10, 11 and 16 points, respectively.

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