(CNN)All in for Ohio!
No Republican has ever won the presidency without capturing the state's electoral votes, which now stand at 18. The last Democrat to make it to the White House without winning Ohio was John F. Kennedy.
Now, Hillary Clinton and Donald Trump are making a beeline for the Buckeye State as the general election season rolls forward.
Since the primaries ended June 7, Trump has logged four visits to Ohio for rallies, in addition to his time at the Republican National Convention in Cleveland. He held an event Monday afternoon in Columbus. Clinton made four stops in Ohio at the beginning of the summer, and ended July on a three-city bus tour, stopping in Youngstown, Cleveland and Columbus.
The importance of the state is clear. Clinton shouted to her supporters in Youngstown Saturday night: "We'll be back! We'll be in the Mahoning Valley. We'll be all over Ohio!" Trump echoed during his Columbus rally Monday: "I'll be back so much you'll be sick of me. We have to go. We have to win this election!"
The attention isn't just in person. It's also over the airwaves. Clinton and her super PAC has so far spent about $13 million dollars in TV ads in Ohio. Television spending in support of Trump, by contrast, has only hit the $1.6 million mark. The super PAC "Rebuilding America Now" and the National Rifle Association's "Political Victory Fund" have produced and aired ads supporting Trump. Trump's campaign has spent zero dollars on ads in the state.
More than seven-and-a-half million voters are up for grabs, but there's a push and pull over registering even more. Federal judges recently struck down several sections of two voter ID laws passed by the Republican-led legislature in 2014; the laws require voters to provide verification of their identity when casting absentee or provisional ballots, prohibits poll worker assistance, and reduces the amount of time voters can correct errors.
Ohio Secretary of State Jon Husted is also facing legal challenges to the state's purge of voters from the register rolls who haven't voted in six years. Husted argued it is all part of the regular maintenance of the voter rolls to account for people who have died or moved, but several parties are fighting the move. A federal judge upheld the purge, but the Sixth Circuit Court of Appeals is now reviewing the decision.
Husted insists his office is looking to increase voter involvement; the state is partnering with the Electronic Registration Information Center ahead of the election to track down people who are eligible to vote, but not registered. Officials estimate they will contact 1.6 million people by mail, and those people will have until October 11 to register to vote.
But, in the end, voter registration efforts only count if there's voter turnout.
John Green has studied Ohio politics and elections for 30 years as director of the Bliss Institute of Applied Politics at the University of Akron.
"The ground game really matters," stressed Green, "particularly in a year where both of the major candidates have a lot of negatives."
Ohio, though, is a complicated place to campaign.
"The state has 8 significant cities," Green said. "Most states are dominated by one or two big cities, but Ohio has a lot of cities and each has their own media market, their own newspaper, political culture, their own way of doing things. To campaign effectively in Ohio, one has to really understand the complexity of the state."
Clinton's team has field offices sprouting up around the state, and her camp is counting on courting suburban women who may be turned off by Trump.
Aaron Pickrell is a senior adviser for Hillary for Ohio and says "there are a lot of people, especially in suburban Ohio, who may have voted for Mitt Romney last time."
"They're going to be turned off by the toxic rhetoric of Donald Trump," Pickrell said.
Ohio GOP officials say Trump's field offices will start opening next week. However, the state party already has 50 paid staff members, and more than 300 volunteers working through the Republican Leadership Initiative. GOP officials insist that Trump's unconventional tactics mean they haven't lost any ground.
"With the Clinton operation, I think they're trying to do a lot to compensate for a weak candidate," said Rob Frost, Cuyahoga County GOP Chair. "What we've got with Donald Trump is a candidate who is taking his message right to the people, through his rallies, through Twitter, through the media."
But Trump may need to repair his relationship with many of the state's Republicans. He's been in an ongoing feud with the popular two-term governor John Kasich. Kasich refuses to endorse Donald Trump, and didn't appear at the Republican National Convention in Cleveland.
Frost says the refusal to endorse could be worse, pointing out that Kasich didn't stage a Ted Cruz-like "vote your conscience" outburst at the Convention, and instead has stayed mostly quiet.
"I know the Trump team isn't happy," Frost said. "And it looks like neither side is happy now. While the bridge wasn't crossed, it also wasn't burned."
The emotions are strong for both candidates across Ohio.
Jake Kerola is 28-years-old and runs a trucking business near Youngstown, Ohio. He is an adamant Trump supporter, and is looking to the billionaire businessman to improve the economy.
"We were booming in the steel industry. Everybody had a job," Kerola said. "This was a good place to come and live and find a job and work and raise a family. Unfortunately it's not (anymore)."
Kerola continued, "I would like to see Trump because he does come from outside Washington. I cannot stand politicians. They say one thing and they go do another."
But Brandy Marino says Clinton is the only one with enough compassion to lead the country. The mother of five from Howland, Ohio said, "I just recently got into politics within the past year and I absolutely love everything that she stands for."
She went on: "I watched the Republicans and it was just. ...I didn't hear anything positive. I didn't hear any platforms, anything. All I heard was a man cutting down everybody and making us hate each other. I don't agree with that. It makes me sick."
Linda and Jack Uhl, however, are a couple divided. Jack Uhl plans to vote for Trump, but is skeptical of the intense focus on Ohio.
"The candidates are vying over these swing states so aggressively they come in and platform all their ideals," he said. "They don't know whether they're telling you the truth or telling you what you want to hear."
His wife, Linda, is a registered Republican, but isn't on the side of either candidate so far.
"I'm not sure about Trump. I'm not sure about Hillary," she said. "I don't know. I think I'm going to make my decision that day."