Three polls in two weeks show an advantage for Democrats in the Hawkeye state, but there are still unanswered questions that could change the shape of the race.

The Des Moines Register’s venerable Iowa Poll, conducted in the week following the Republican convention by Ann Selzer, found that 52 percent of likely voters in Iowa supported Sen. Barack Obama, the Democrat, and 40 percent supported Republican Sen. John McCain. The margin of error was four percentage points, putting Obama ahead by a statistically significant margin.

A Pollster.com average of polls shows a widening lead for Sen. Barack Obama in Iowa.

A Pollster.com average of polls shows a widening lead for Sen. Barack Obama in Iowa.

The Big Ten Network and the University of Wisconsin released a poll last week showing a 45-45 percent tie at the presidential level in Iowa. But the poll also indicated that a very large percentage of Iowans — more than three fourths — believe the nation is on the wrong track, even though a majority — 57.1 percent — believe Iowa’s Democrat-led state government is on the right track. A plurality of Iowans believed that Obama “shares my values,” and President George W. Bush is viewed “very” or “somewhat” unfavorably by 62.7 percent.

And a Sioux City Journal poll, released over the weekend and conducted about the same time as the Big Ten Network’s poll, showed Obama with a 53-39 percent lead over McCain. Obama led among men, women, and independents, who preferred him by an even wider margin than the general sample of likely voters.

If campaign spokespeople on both sides are to be believed, Iowa is still a hotly contested swing state. Republican insider Doug Gross told the Sioux City Journal, “Iowa’s still very much in play and will continue to be in play and is neck and neck.” Obama State Director Jackie Norris said “we are taking absolutely nothing for granted.” And in an interview last month with the Iowa Independent, McCain’s midwest campaign director, Gentry Collins, said, “In Iowa, we’re making a very large investment.”

But campaign spokespeople always say that. A look at the numbers tells a slightly different story.

Although the Big Ten Network’s poll, which pegged the race for Iowa’s seven electoral votes as a dead heat, caused Democrats some concern when it was released, most fears have calmed after the Sioux City Journal’s poll confirmed the results of the Register’s Iowa Poll, giving Obama a double-digit lead.

And regardless of the so-called “top-line” results of the three polls, the more specific questions about whether the country is on the right track, what the most important election issues are, and which candidate “shares my values” are almost universally encouraging. Even before the high-profile economic meltdown of the past two weeks, the Register’s Iowa Poll said that voters here consider the economy their top voting issue, and that Obama is seen as most capable of handling it. The Sioux City Journal’s poll confirmed this result. The Big Ten Network’s poll indicated that Iowans oppose the direction of the federal government but support the direction of state government.

In all, it appears Obama is headed to a fairly comfortable victory in the Hawkeye state, but Democrats still have reasons for worry.  Here are a few potential X-factors:

Down-ticket drop-off?

One big question is whether Obama’s tidal wave of new supporters — brought into the Democratic party in large part by his successful Iowa caucus campaign — will choose to vote in state and local races at all. In general, most Democrats can be trusted to vote “straight ticket,” but with a candidate known for so-called “post-partisanship,” the question may be more relevant this year.

Add to that the fact that Obama’s ground game is not associated with the traditional “coordinated campaign,” which Democrats traditionally use to pool the resources of all candidates on the ballot to form one big field operation, and this factor becomes a cause for concern.

Will turnout surge?

Another open question is turnout, which surged during the the caucuses earlier this year, propelling Obama to victory. Many believe that for Obama to succeed in November, turnout must surge again.

But turnout tends to increase most when races are competitive. In Iowa, Sen. Tom Harkin and four of Iowa’s five congressmen are likely to cruise to victory with comfortable, double-digit margins. That means that GOTV efforts will fall squarely on the Obama campaign’s shoulders. Incumbents will certainly spend some of their resources campaigning and turning out supporters, but it will not be close to what Iowa saw in 2006, because, by and large, the state’s federal incumbents are feeling safe.

Local politics in the mix

It remains to be seen how local and state-based political issues might shape the decisions Iowa voters make this November.

In Cedar Rapids and Iowa City, where Democrats traditionally run up large margins that help carry them to victory in statewide races, flood recovery weighs heavily on voters’ minds. While so far the issue does not appear to significantly benefit either Democrats or Republicans, there is a chance that further inaction on recovery funding will begin to make a dent in state and federal Democrats’ approval ratings.

Across the state, social conservatives have attempted to rally the Republican base behind efforts to amend the Iowa constitution to ban same-sex marriage. But in worsening economic times, when the nation is engaged in two wars, the issue seems to be resonating less than it did in 2004 and 2006. That could all change if the Iowa Supreme Court acts before election day to uphold the Polk County court decision that overturned the state’s Defense of Marriage Act.

And, in the increasingly unlikely event that the governor calls a special session of the state legislature to appropriate funds to flood recovery, the anti-gay marriage groups could again protest outside the capitol, gaining valuable press coverage even in the absence of a supreme court ruling.

But the local issues that could play out here between now and November might not all work against the Democrats. When it comes to agricultural interests, at least, Iowans may be more likely to rally behind Obama. McCain, who opposed the last two farm bills and wants to cut farm subsidies from the federal budget, is not likely to have the full force of the powerful Farm Bureau, which the GOP can usually depend on in presidential races, behind his campaign. Agricultural interest groups seem to be breaking from past tradition and either endorsing Obama, a Democrat who hails from an agricultural state himself, or declining to endorse either candidate.

So, while conditions here appear to favor Democrats at all levels of government, one September or October surprise could still call Iowa’s seven electoral votes into question.