President Trump is on his way to Ohio ahead of the debate tonight and while he didn't speak to reporters before departing, his chief of staff Mark Meadows said that Trump was essentially done preparing for the debate and added that he was in a good mood.

Meadows said that some of the debate guests would be traveling on Air Force One, but didn't name names. However Alice Johnson, who Trump pardoned last month, was spotted boarding.

In addition to Johnson, the pool traveling with the president so far has spotted Lara Trump, Eric Trump, Tiffany Trump, Donald Trump Jr. and Kim Guilfoyle aboard Air Force One.

-ABC News' Katherine Faulders

Despite Republican successes in statewide races in Ohio since 2016, the Buckeye State has become increasingly competitive as Trump and former vice president Joe Biden prepare to face off in Cleveland for their first debate on Tuesday.

In recent weeks Trump and Vice President Mike Pence have traveled repeatedly to Ohio, where they defeated Hillary Clinton and Sen. Tim Kaine, D-Va., her vice presidential candidate, in 2016, 51% to 43%.

Republicans also performed well statewide two years ago, winning the gubernatorial race and other down-ballot contests.

“Ohioans showed up for President Trump in 2016 and we expect them to do the same this November,” Trump campaign spokeswoman Samantha Zager told ABC News.

The president’s campaign has had a permanent presence on the ground in Ohio since 2016, and said they have made more than 10 million voter contacts in the state, where they and other GOP groups continue to canvass on the ground during the coronavirus pandemic.

The Biden campaign, meanwhile, has relied on virtual and digital organizing in the state during the pandemic, and has hosted hundreds of events and held 450,000 conversations with voters over the last month. Following Tuesday's debate, Biden will take a train tour of the state on Wednesday.

Biden has delivered a sharp economic message focused on Trump's record, centered on Toledo and Youngstown, home to several car plants and many blue-collar voters who abandoned Democrats and voted for Trump for years ago.

He's run at least eight television ads in recent weeks, including a response to Trump's call for a ban on Goodyear, the Ohio-based tire company than ran in Akron, where the company is based.

In an election year reshaped by the coronavirus pandemic, it’s also playing host to a number of legal battles over access to ballot drop boxes, which are increasingly used by voters as an alternative to in-person voting or relying on the United States Postal Service, amid concerns about service delays.

Read more about the battle for Ohio here.

-ABC News' Ben Siegel and Adia Robinson

An immutable fact of politics in the era of President Donald Trump is that there's no separating the president from his base.

Yet an ABC News/Washington Post poll released Tuesday morning out of critical Pennsylvania -- FiveThirtyEight's most likely tipping-point state -- brings new evidence that Trump can't bank on the range of supporters he once did.

The poll shows former Vice President Joe Biden leading Trump 54-45 among likely voters, mirroring the results of the ABC/Post national poll released Sunday. Hillary Clinton backers from 2016 support Biden 98-1 in the Pennsylvania poll, while Trump's supporters from last time break 92-8 in his favor.

This does not mark a mass exodus. But it suggests a narrowing coalition, Wisconsin and Michigan -- all states won by Trump by less than a percentage point, in a region Trump and Biden are set to visit in the days after Tuesday night's first presidential debate.

There won't be many, or perhaps any, singular moments as critical as this first debate in terms of changing the trajectory of the race. Trump wants and needs to effectively disqualify Biden as an alternative -- to make the campaign about Biden more than himself.

Biden will be trying to avoid a brawl of an insult-fest. He will be seeking to keep the campaign focused on COVID-19 and the economy -- about Trump and his leadership, in a campaign that's been more steady than not.

-ABC News Political Director Rick Klein

ABC News Chief Global Affairs correspondent Martha Raddatz joins ABC News' Start Here podcast to talk about her experience moderating debates with both President Donald Trump and former Vice President Joe Biden before the two go head-to-head for the first time Tuesday night.

TRUMP'S CLAIM: Can you imagine where they say you have to have your ballot in by Nov. 10? Nov. 10. That means that's seven days after the election, in theory, should have been announced. We have major states with that -- all run by Democrats, all run by Democrats. It's a fraud. It's a rigged election.

FACT CHECK: It is true that mail ballots arriving after Nov. 3 will be counted in several states, but these ballots are not fraudulent.

For these mail ballots to be counted, they must be postmarked on or before Election Day, and in some states, they must be postmarked by the day before the election.

In a normal election year, 19 states accept ballots that arrive after the election, as long as they are properly postmarked and arrive within a state-specific timeline, between three and 14 days post-election, according to the National Conference of State Legislatures. These states are not "all run by Democrats" either. Alaska, Iowa, Maryland, Mississippi and Ohio -- all states with Republican governors currently -- have postmark-by deadlines on the books, even when there isn't a pandemic causing widespread changes to voting.

More states will have postmark-by deadlines for the November election, due to both court rulings and changes implemented by state officials.

In Wisconsin on Tuesday, for example, a federal appeals court upheld a lower court's ruling, which ordered county election officials to accept ballots received up to six days post-election as long as those ballots were postmarked on or before Nov. 3. Other battleground states where court rulings have extended the deadline for mail ballots to arrive include Michigan, Pennsylvania and Georgia, but the extension is being challenged in all three states.

In Kentucky, Democratic Gov. Andy Beshear and Republican Secretary of State Michael Adams reached a bipartisan agreement in mid-August to accept ballots returned by mail through Nov. 6, as long as those ballots are postmarked on or before Nov. 3.

-- ABC News' Quinn Scanlan