[cnn-photo-caption image= http://i2.cdn.turner.com/cnn/2008/images/10/22/art.mccain.bush.jpg caption="A new poll suggests John McCain is on defense in states Pres. Bush won."]
WASHINGTON (CNN) - New polls suggest that John McCain is on defense in four of five states that President Bush won in the last election.
CNN/Time Magazine/Opinion Research Corp. surveys released Wednesday afternoon indicate that Barack Obama has a small advantage in Ohio, Nevada, North Carolina and a large lead in Virginia, with John McCain ahead in West Virginia.
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Democrats last carried North Carolina in a presidential election in 1976, but the poll suggests that Obama, D-Illinois, has a 4-point margin - 51-47 percent - over McCain among likely voters. That is with within the poll's sampling error, but it is an increase over our last survey in North Carolina two weeks ago, when Obama was tied at 49 percent with McCain, R-Arizona. Fifteen electoral votes are at stake in North Carolina.
"The North Carolina poll exhibits the same gender gap and generation gap that national polls typically show," CNN Polling Director Keating Holland said. "McCain has a slight edge among men and voters over 50 years old; Obama has a slightly bigger margin among women and younger voters."
You have to go back to 1964 to find the last time Democrats won Virginia in a presidential contest. But the poll indicates that Obama continues to hold a comfortable lead over McCain in Virginia, 54-44 percent. Obama held a similar 10-point advantage over McCain in our poll from last week.
"Obama's lead in Northern Virginia is growing," Holland noted. "He now beats McCain 2-1 in the Washington suburbs." Virginia has 13 electoral votes.
It all came down to Ohio four years ago, with the state putting Bush over the top in clinching his re-election. And our new poll suggests that it could again all come down to Ohio and its 20 electoral votes. Fifty percent of likely voters in Ohio questioned in the poll back Obama for president, and 46 percent support McCain. Obama's lead is within the poll's sampling error.
Suburban voters could again be crucial to determining the outcome in Ohio.
"The suburban vote in Ohio is split right down the middle, 48 percent to 48 percent," Holland said. "That's a familiar pattern for anyone who follows Ohio politics. Four years ago, the suburbs in the Buckeye State went for George W. Bush 51 percent to 49 percent."
Nevada voted for Bush in the past two elections, but the survey suggests Obama retains a small advantage in the state, 51-46 percent. The lead is also within the poll's sampling error.
Bush carried West Virginia by 13 points in 2004 but the poll indicates McCain has a smaller 9-point lead over Obama, 53 percent to 44 percent.
There's an interesting trend in these five new polls.
"In every one of these states the decline in the Republican vote is larger than the gain the Democratic vote," said CNN Senior Political Analyst Bill Schneider. "One reason is there may still be uncertainty among voters about Obama, but there's no uncertainty about the loss of confidence in the Republicans.
"The two states where we see the biggest shift in the Democrats' favor are Virginia and North Carolina, which have the largest populations of African-American voters. Democrats have made a gain of 9 points in Virginia and 7 points in North Carolina from the results of the 2004 presidential election," Schneider added.
With these new polls factored in, the CNN Electoral College Map estimates that if the election were held today, Obama would win states with 277 electoral votes, with McCain taking states with 174 electoral votes. States with 87 electoral votes are still up for grabs. Two-hundred and seventy electoral votes are needed to win the White House.
State surveys, campaign advertising buys, candidate visits, and voting trends are all taken into account in calculating the CNN Electoral College map.
Likely voters questioned in the polls were also asked about whether they would support either of the three major third-party candidates, Independent Ralph Nader, Libertarian candidate Bob Barr, and Green Party candidate Cynthia McKinney. But none of the three registered more than 3 percent of the vote in any of the five states surveyed.
The CNN/Time Magazine/Opinion Research Corp. polls were conducted Sunday through Tuesday, with 700 likely voters in Nevada, 644 likely voters in North Carolina, 737 likely voters in Ohio, 647 likely voters in Virginia, and 674 likely voters in West Virginia questioned by telephone. The survey's sampling error is plus or minus 3.5 percentage points in Nevada and Ohio and plus or minus 4 percentage points in North Carolina, Virginia and West Virginia.