Another slate of battleground-state polls released late Thursday confirms that President Obama holds a clear, if tenuous, advantage in the race to 270 electoral votes, reaching 50 percent in smaller swing states Colorado, Iowa, and Wisconsin. The polls, conducted by Marist College for NBC News and The Wall Street Journal, show Obama with slight leads over Mitt Romney in Colorado and Wisconsin, and a significant lead in sparsely polled Iowa, where early voting begins next week.
A separate CNN/ORC International poll, also released on Thursday, showed Obama slightly ahead in Nevada, 49 percent to 46 percent. That is within the poll's margin of error.
Obama leads Romney in Colorado, 50 percent to 45 percent, the poll shows. One percent of likely voters prefer another candidate, and 4 percent are undecided. Obama's lead is built on an 11-point edge among independents, 50 percent to 39 percent.
Men favor Romney by 5 percentage points, 50 percent to 45 percent. But women swing to Obama by a wider, 14-point margin, 54 percent to 40 percent.
The race is closer among those voters who describe themselves as highly enthusiastic, with Obama leading by just 1 point. But Obama leads by 8 points among voters who "strongly support" their preferred candidate.
The poll compares to a smaller, 1-point Obama lead in a CBS News/New York Times/Quinnipiac University poll also released this week.
Obama leads Romney on other measures outside of the ballot test. A majority of likely voters, 51 percent, have a favorable opinion of Obama, compared with 45 percent who have an unfavorable opinion. But half have an unfavorable opinion of Romney, while just 43 percent view him favorably.
Voters are split on which candidate would do a better job handling the economy: 48 percent pick Obama, versus 46 percent for Romney. Obama holds a wider, 10-point edge on foreign affairs; the poll was conducted after the incidents at U.S. missions in Egypt and Libya last week.
Obama holds a significant, 8-point lead in Iowa, 50 percent to 42 percent, according to the poll. Eight percent are undecided or prefer another candidate.
Though each candidate wins roughly nine in 10 of his own partisans, Obama leads by 10 points among independents, 49 percent to 39 percent.
The two candidates run neck-and-neck among men: 47 percent for Romney, versus 45 percent for Obama. But Obama holds a commanding lead among female voters, 55 percent to 37 percent.
The NBC News/Wall Street Journal/Marist poll is the first reliable, live-caller poll in Iowa since Romney became the presumptive Republican presidential nominee in late May.
Obama holds a particularly strong lead among the 27 percent of voters who say they will cast their ballots before election day. Early and absentee voters tilt heavily for Obama, 65 percent to 29 percent. In-person early voting begins Sept. 27.
Iowa voters also have a negative impression of Romney. Half view him unfavorably, compared with just 42 percent who have a favorable opinion. Obama's image rating is more positive: 53 percent favorable, 42 percent unfavorable.
By a 4-point margin, Iowa voters think Obama would do a better job handling the economy, 47 percent to 43 percent.
The new poll, which shows Obama leading, 50 percent to 45 percent, is the third live-caller poll in the Badger State this week. The results more closely resemble a CBS News/New York Times/Quinnipiac University poll showing Obama leading by 6 points than a Marquette Law School poll that showed Obama ahead by a wider, 14-point margin.
Each candidate wins 95 percent among members of his own party, with Obama holding an insignificant, 1-point lead among independents. Romney leads by 3 points among men, while Obama holds a wider, 12-point advantage among women.
The candidates were tied among high enthusiasm voters, but Obama holds a slight edge among voters who strongly support their candidate.
Voters were split on which candidate would do a better job handling the economy: 46 percent for Romney, and 45 percent for Obama.
Wisconsin voters retain a positive impression of Rep. Paul Ryan, R-Wis., the poll shows. Forty-nine percent of likely voters have a favorable opinion of Ryan, while 40 percent view him unfavorably.
The NBC News/Wall Street Journal/Marist polls were conducted Sept. 16-18. The poll surveyed 971 voters in Colorado, 898 in Iowa, and 968 in Wisconsin. The Colorado poll carries a margin of error of plus or minus 3.1 percentage points, while the Iowa survey's margin of error is plus or minus 3.3 percentage points and the Wisconsin poll's margin of error is plus or minus 3.2 percentage points.