Updated

Barack Obama leads John McCain by 46 percent to 39 percent, according to a FOX News national registered voter poll released Friday. Two weeks ago Obama led by 45 percent to 39 percent (Sept. 22-23).

Obama's advantage comes mainly from doing better among women, blacks, young voters, those with a college degree, and unmarried voters. He has increased his edge over McCain among women to 16 percentage points, up from a 4-point edge last month (Sept. 8-9).

Obama has also improved his standing with his party faithful. A month ago, 79 percent of Democrats were backing Obama. Today it is 86 percent. McCain has consistently received the backing of over 80 percent of Republicans and is backed by 83 percent today.

Independents split their vote 34 percent Obama and 32 percent McCain, with 24 percent unsure. That's little changed from two weeks ago when Obama was up by 36 percent to 31 percent and 29 percent undecided.

A 61 percent majority of voters believes Obama is going to win the election — more than three times as many as believe McCain will (18 percent). A month ago it was evenly divided: 41 percent Obama and 40 percent McCain (Sept. 8-9). This summer, voters were more likely to say Obama would win: 51 percent Obama and 27 percent McCain (July 22-23).

All of the interviews for the poll were conducted after the town-hall style presidential debate held on Tuesday, Oct. 7. Opinion Dynamics Corp. conducted the national telephone poll of 900 registered voters for FOX News from Oct. 8 to Oct. 9. The poll has a 3-point error margin.

There is no doubt the economy remains the single most important issue to voters this election. It is picked by 49 percent, which is more than all the other issues combined.

By 50 percent to 35 percent, Obama tops McCain as the candidate voters trust to handle the economy. Obama has the edge on all other issues tested save two — on handling the war on terrorism McCain is preferred by 14 points and on Iraq by 5 points.

The Obama-Biden ticket has a clear advantage on "having better judgment" (+ 7 points), "bringing the right change to Washington" (+ 15 points), "better understands American families and their problems" (+ 24 points). By a slim margin the Democratic ticket is also seen as better understanding "America's importance in the world" (+ 3 points).

The McCain-Palin ticket has a significant edge on "having more experience" (+ 28 points).

What about the gut check question? If you had to make the toughest decision of your life, which candidate would you go to for advice? 42 percent say Obama and 41 percent McCain. That's a significant shift from a month ago when 50 percent said they would go to McCain and 34 percent Obama (Sept. 8-9).

Among independent voters: 37 percent say they would go to McCain for advice and 32 percent Obama and 22 percent say neither.

Interest in the Election and Enthusiasm for Voting

Identical majorities — 58 percent — of Democrats and Republicans say they are "extremely" interested in the presidential election. And roughly equal numbers of Obama supporters (86 percent) and McCain supporters (83 percent) say the outcome of the election matters "a great deal" to them.

Almost all of each candidate's backers say they are certain of their support. Fully 89 percent of Obama's supporters say they are certain to vote for him, up from 85 percent in August. There is matching conviction for the Republican candidate: 91 percent of McCain's supporters describe their vote as certain, up from 86 percent in August.

In addition, a higher number of Democrats (62 percent) than Republicans (52 percent) say it is "extremely" important to them that their candidate wins. Similarly, Obama supporters (61 percent) are more likely to say it is "extremely" important to them that their candidate wins than McCain backers (49 percent).

Majorities of Obama supporters and McCain supporters say their vote is more a vote for their candidate than against the other candidate. Seventy-seven percent of Obama backers say they are voting for him rather than against McCain. Among McCain supporters, 65 percent say their vote is more for him than against Obama.

On the flip side, 28 percent of McCain backers describe their vote as being more against Obama. For Obama supporters, 17 percent say their vote is against McCain.

Importance of the Race and Age of the Candidates

Although many voters say race will not play a factor in their presidential vote decision, 45 percent say it will. Some 5 percent say the race of the candidates will be the "single most important factor" in deciding their vote, while 19 percent say it will be "one of several important factors" and another 21 percent say "a minor factor."

A 52 percent majority says the race of the candidates will not be a factor "at all."

Forty-seven percent of Obama supporters and 45 percent of McCain supporters say race will be a factor in their vote.

About 4 in 10 blacks (42 percent) and 4 in 10 whites (46 percent) say race will be a factor in deciding their vote. Among white voters who consider race a factor, 45 percent back McCain and 41 percent Obama. Almost all of the blacks who consider race a factor back Obama.

Six of 10 voters say the age of the candidates will play a factor in their vote. Here's how it breaks down: 5 percent say age will be the "single most important factor," 23 percent say "one of several important factors" and 32 percent say "a minor factor."

Some 39 percent say the age of the candidates will not be a factor in choosing a candidate.

Bush and Congress Approval Hit New Lows

Most Americans give negative ratings to President Bush: 69 percent disapprove — nearly three times as many as the 25 percent who approve of the job he is doing as president. That's the lowest approval rating Bush has received during his presidency.

Similarly, Congress gets its lowest rating ever, with just 13 percent assigning positive job marks, and 77 percent giving negative ratings.

Click here to see the raw data.