NBC News/Wall Street Journal/Marist released its latest Iowa poll today, which shows President Barack Obama ahead of Republican Mitt Romney by 51 percent to 43 percent among likely voters. It’s the best poll result for the president in Iowa this month. We Ask America conducted a one-day survey in Iowa on October 15 and found Obama ahead by 48.7 percent to 45.9 percent, with Libertarian Gary Johnson at 1.2 percent. American Research Group found Obama and Romney tied at 48 percent in its poll that was in the field between October 11 and 14. Rasmussen Reports found Obama leading 49 percent to 47 percent in a one-day poll taken October 7.

Details on the NBC/WSJ/Marist poll are after the jump. Early voting and the gender gap are the key components of Obama’s advantage in Iowa.

NBC’s Mark Murray summarized the findings from the latest poll, which was in the field from October 15 through 17.  The survey reached 1,137 “likely voters,” producing a margin of error of plus or minus 2.9 percentage points. The full polling memo is here (pdf); it also includes results from the September poll by the same firm.

The second presidential debate did not appear to change many minds. Murray notes,

[I]n the day prior to the debate, Obama was ahead of Romney in Iowa by nine points among likely voters, 52 percent to 43 percent. The day after, the lead was eight points, 51 percent to 43 percent.

The gender gap persists, with Obama ahead among female likely voters in Iowa by 57 percent to 38 percent. Romney leads by single digits among male likely voters.

About 48 percent of respondents said things are generally moving in the right direction, while 47 percent said the country is off on the wrong track. That’s an improvement from last month’s NBC/WSJ/Marist poll in Iowa, which found “right direction” at 43 percent of likely voters and “wrong track” at 49 percent.

Absentee voting in Iowa is on track to set a record this year. Murray commented,

What especially seems to be helping Obama in Iowa is early voting. Thirty-four percent of likely voters in the poll say they have already cast their ballots, and the president is winning those people, 67 percent to 32 percent. Another 11 percent are planning to vote early, and he’s up among that group, 55 percent to 39 percent. But it’s reversed among Election Day voters: Romney is ahead, 54 percent to 39 percent.

For Obama to be leading among early Iowa voters by a two to one margin, he would need to be getting most of the votes from independents who have cast absentee ballots so far. The Iowa Democratic Party has done a lot of outreach among no-party voters identified as supporters of previous Democratic presidential candidates.

Iowa Democrats have also invested significant time and money into voter registration drives and turnout events on college campuses. Young people are less likely than older generations to identify with a political party. This week the Obama campaign held “campus takeover” events in many college towns around the state. The president himself spoke at Cornell College in Mount Vernon. Bruce Springsteen drew a large crowd at Hilton Coliseum in Ames today.

Republicans are stepping up their GOTV in Iowa as well. Earlier this week, I received another voter mobilization robocall paid for by the Republican National Committee, and a personal call from someone in the GOP’s “victory” office in Urbandale. Today I listened in on part of a Paul Ryan telephone town hall with Iowa supporters. He encouraged them to vote early so that they will be able to help turn other people out to vote on November 6. I also got a robocall from a conservative interest group featuring the voice of Mike Huckabee, which was targeting “pro-life” voters.

The NBC/WSJ/Marist poll may be overstating Obama’s support here. Murray comments, “the Iowa poll shows Democrats with a two-point party-identification advantage over Republicans; the 2008 exit poll had Democrats with a one-point edge.” If the GOP benefits from an “enthusiasm gap,” as many polls suggest, then winning Iowa is still within reach for Romney.

National tracking polls are showing a mixed picture this week. Gallup sees Romney ahead and above 50 percent nationwide.

As a supporter of electing the president by national popular vote, I have been wondering whether it would help that cause for Romney to win the popular vote but lose the electoral college. My hunch is no, because Democratic support for national popular vote reform would drop significantly if the electoral college saved Obama’s presidency. Although many Republicans would no doubt portray Obama’s victory as illegitimate, I doubt they would seek to abolish the electoral college, because it is perceived to benefit small states–most of which lean Republican.

Any comments about the presidential race are welcome in this thread.