The fifth in a 10-part weekly series

It’s Election Day in Iowa.

Early voting officially begins Thursday in the Hawkeye State, a key battleground that President Obama won twice. This cycle, it could swing back toward Republicans with their unlikely, but nonetheless fitting, nominee.

Last November, Donald Trump seemingly torpedoed his chances when he issued the knock heard ’round the political world: “How stupid are the people of Iowa?” he asked during a rally in Fort Dodge as his then-rival, Ben Carson, was surging in the first-in-the-nation caucus state. The dig added to the litany of challenges facing the thrice-married businessman and reality-television star in the evangelical-heavy state.

As the political world would soon learn, Trump’s missteps in Iowa, and elsewhere on the campaign trail, had little negative impact on his standing. (It was in the summer of 2015, speaking at the state’s Family Leadership Summit, that Trump criticized John McCain for having been a prisoner of war.)

Now, as this November approaches, Trump finds himself leading Hillary Clinton there by 4.8 percentage points, according to the RealClearPolitics polling average.

Trump’s appeal in the caucuses -- he finished second, just four percentage points behind Ted Cruz, whose campaign was tailor-made for the primary electorate -- might have been perplexing at the time, given that Republican caucus-goers tend to be more conservative and religious. But the overall electorate could be ripe for the GOP nominee.

According to census data, 92 percent of Iowans are white, and just 26 percent have a college degree -- demographics in line with Trump’s base of support.

A recent Monmouth University poll found Trump’s lead fueled by independent voters in the state. The survey found the two candidates tied among voters with a college degree, and Trump leading by 13 points among those without. A Quinnipiac University survey found a gender gap favoring the real estate tycoon. Trump has a sizable lead among men, 52 percent to 26 percent, while Clinton leads more narrowly among women, 47 percent to 37 percent.

Iowa is considered a purple state, but Democrats have carried it in six of the past seven presidential elections there. Al Gore won by less than a percentage point in 2000 and George W. Bush by a similar margin in 2004. Obama won in 2008 by nearly 10 points, but by five in 2012.

Until 2015, Iowa had for decades been represented in the U.S. Senate by the progressive Tom Harkin and the conservative Chuck Grassley. That’s when Republican Joni Ernst, the first woman to represent Iowa in Congress, succeeded the retiring Harkin, defeating Democratic Rep. Bruce Braley by eight points. Ernst won white, non-college-educated men overwhelmingly, and tied overall among women in the state.

Obama’s wins here were bolstered by his support among working-class white voters, a demographic group that has been trending away from Democrats. Trump’s economic populism has drawn those voters to his side in various states, and Iowa could be no different.

“One of the reasons Trump is doing well in Iowa is his economic message plays very well up and down the Mississippi River,” said GOP strategist Craig Robinson, referring to a blue-collar area of the state focused on industry and manufacturing and home to independent voters. “When Trump talks tough about American business picking up and taking manufacturing jobs overseas, that’s a message that hits home to a lot of people and crosses party lines. That’s why he has been stronger in Iowa than any other battleground state.”

Trump's economic message "hits home to a lot of people and crosses party lines. That’s why he has been stronger in Iowa than any other battleground state.” GOP strategist Craig Robinson

Iowa offers just six electoral votes, and unlike some of its Midwestern neighbors, isn’t likely to swing the election. The candidates haven’t camped out there as they have in Ohio and Pennsylvania, though the state will play an important role for both, and for their respective parties.

Clinton has pathways to the White House that don’t depend on Iowa, but a win there would provide a cushion for her and would indicate avenues were closed for Trump in the Midwest. Moreover, a defeat could solidify a shift in the Democratic coalition moving forward.

For Trump, whose path to the White House is narrower, a victory in Iowa is critical. Conversely, a loss in a place where demographics overwhelmingly play to his favor would be a sign of serious trouble elsewhere.

“This is why we are all watching closely: to figure out whether this is an election where fundamentally, party coalitions shift,” said Rachel Caufield, political science professor at Drake University in Des Moines. Iowa, she said, is key to that calculus.

In addition to favorable demographics, Trump has on his side the GOP cavalry in the state, led by Terry Branstad. The popular governor is the longest serving in U.S. history and has an extensive network in the state. Branstad has embraced Trump and helped to rally the party behind him. While officially neutral in the caucuses, Branstad criticized Cruz for his support of ending ethanol subsidies. The governor’s son, Eric, led a pro-ethanol group that campaigned against the Texas senator during the caucuses, and now runs Trump’s general election campaign in the state.

“We’ve got to be one of the very few states that has every single one of our statewide officials, our governor and lieutenant governor and every federal official that is behind him,” said GOP state Chairman Jeff Kaufmann. “I think our state and our party leaders have absolutely been very proactive. And I think the stars are all aligning here.”

“We’ve got to be one of the very few states that has every single one of our statewide officials … behind [Trump].” GOP state Chairman Jeff Kaufmann

Trump has visited Iowa four times since accepting his party’s nomination, including a visit to Council Bluffs on Wednesday, where he touted the recent endorsement of Ted Cruz.

“I have never seen this kind of excitement ever in my lifetime,” said Eric Branstad. “People want change. They are tired of this Washington message, the status quo, and being on the wrong track.” Trump’s economic message, he noted, “is resonating with working Iowans because they want to see those manufacturing jobs back.”

The Trump campaign has frequently deployed running mate and Midwesterner Mike Pence in an effort to rally conservatives. The Indiana governor made the rounds at the famed Iowa State Fair in July, in place of Trump. Just last week, he visited twice.

State Democrats believe Trump’s crossover appeal is limited, though they recognize independents are key.

“If you're a registered Democrat, you're probably not a crossover candidate. But if you're an independent, lower on the economic scale, non-college, voted Obama in the past, you might be a place the Trump campaign can appeal,” said Democratic strategist Jeff Link, who ran Gore’s successful 2000 campaign in the state.

Link said there are new opportunities available to Clinton and Democrats this cycle, however. Namely, among suburban women in the fast growing areas around Des Moines and Davenport -- voters who supported Mitt Romney but are repelled by Trump’s rhetoric and tone.

“For the last several cycles, we have seen suburban Iowa become more of an open territory for Democrats and that could be solidified for us this cycle,” said Norm Sterzenbach, a Des Moines-based Democratic strategist.

Clinton will be in Iowa Thursday as part of her post-debate battleground-state tour that included North Carolina Tuesday, New Hampshire the following day and Florida on Friday. She had visited the area twice since accepting her party’s nomination in July (with one stop in Iowa and another in Hampton, Ill., part of the Quad Cities area that includes Iowa). But like Trump, she has dispatched her running mate to help drive support. Tim Kaine visited Iowa State University in Ames last week to rally younger voters. With several large universities in the state, these voters could help propel Clinton, though she has been struggling to garner enthusiasm among millennials in national polls. While in Ames, Kaine acknowledged that one of his children supported Bernie Sanders in the primaries, an admission seemingly aimed at bringing young Sanders’ supporters on board. The Vermont senator proved to be competitive with Clinton in Iowa, winning over 80 percent of voters under 30, who made up 18 percent of caucus-goers. During a visit here in August, Kaine also stressed his middle-class upbringing in Missouri.

“Iowa could absolutely be the state that gets Hillary over the 270 mark.” Clinton Campaign Manager Robby Mook

“Iowa is going to remain a top priority for this campaign nationally, particularly because Iowa votes so early in the process,” Clinton Campaign Manager Robby Mook told reporters last week. “When we look at all the different states in the map of the Electoral College, Iowa could absolutely be the state that gets Hillary over the 270 mark.”

Democrats aren’t convinced Trump has a hold on the voters. “The people I talk to know Hillary Clinton is talking about working-class issues and Donald Trump is not,” said Democratic state party Chairwoman Andy McGuire, noting that the issue of college affordability invariably comes up in conversations. “When you’re talking about working-class issues, she has a platform that’s much stronger.”

Clinton gave an economic speech in Iowa in August, her first visit to the state since the caucuses. The now-Democratic nominee eked out a win over Sanders in February, aiming to mount a stronger showing after placing a surprising third back in 2008. Still, her caucus efforts this cycle have given her an organizational advantage for the general election.

Democrats see opportunities in early voting, which contributed to Obama’s past two victories here, and note a 3-to-1 advantage over Republicans in terms of early ballot requests.

On a conference call with reporters last week, Clinton’s Iowa campaign director, Kane Miller, said the team’s goal in the final stretch is “to make sure that all Iowans know what’s at stake, and how easy and convenient it is to vote early.”

The Clinton teams wants “to make sure that all Iowans know what’s at stake, and how easy and convenient it is to vote early.” Iowa campaign director, Kane Miller

While Democrats are ahead of Republicans in terms of early ballot requests this cycle, they are down more than half compared with requests made at this point in 2012, according to an Associated Press report.

Republican requests have remained about the same.

GOP operatives appear confident that Trump will swing Iowa back to the party. But, they caution, even if he wins, his style and rhetoric won’t necessarily be a model for candidates there in the future.

“Trump, one thing about him, he is very blunt even with Iowans, and says he’d rather have a primary system than a caucus system. And Iowans are very, very loyal to our caucus system,” said Kauffman.

“I think Donald Trump will be seen as an exception to the rule, because of his personality, because of his mass appeal, because the stars were lining up out of the frustration,” Kauffman said. “I think his style of campaigning fit him. But I do not believe at all that it will change the way Iowans expect our candidates to come out and court our votes.”

Next week: Millennials

Caitlin Huey-Burns is a national political reporter for RealClearPolitics. She can be reached at chueyburns@realclearpolitics.com. Follow her on Twitter @CHueyBurnsRCP.