CHARLESTON, S.C. — On the surface, Chris Moody and Steve Neal don't have much in common, except for this: They're excited about voting for President Donald Trump again in 2020.

Moody, a white 24-year-old day care worker and recent Marshall University graduate from Charleston, West Virginia, is something of a walking billboard for the president's re-election. He strolled into the King's Leaf Cigar Lounge here Saturday wearing a T-shirt bearing an impressionistic version of Trump's visage and these words: "If Trump is not your president this is not your country. You are not a tree. Move."

He is very tapped into a powerful sentiment stoked by Trump and shared by many of his voters — that the president is under constant and unfair attack from Democrats, the news media and establishment forces in Washington.

"I can't stand the way people talk about him," Moody said.

Neal, a black 49-year-old automotive finance consultant who uses his sparkling white Lexus to drive Uber routes on the side, said that his support for Trump is a source of ribbing inside his family of hard-core Democrats in Charleston and that he seldom talks about his politics unless he's asked.

"My vote speaks strong enough for itself," Neal said.

These two types of supporters figure to factor heavily into Trump's success or failure as he seeks a second term in a presidency that few would have predicted possible when he first descended an escalator at his namesake Manhattan skyscraper four years ago without ever having won a single vote for any office.

Now the undisputed center of the political universe, Trump is set to kick off his re-election campaign Tuesday at Orlando's Amway Center having redefined the Republican Party, the tenor of American public discourse and perceptions of the country at home and abroad. He'll do so with the shadow of a possible high-stakes House impeachment inquiry looming over his shoulder — a prospect that carries peril for him in its potential to publicize special counsel Robert Mueller's findings in painful fashion and, conversely, one that offers the hope that he can rally new voters to his side in the name of defending his presidency from overzealous opponents.

Because while Trump has formed the most loyal base of supporters in modern history, he has also alienated and mobilized large swaths of the electorate, from liberal city-dwelling Democrats to ex-Republican suburbanites turned off by his crass manner, hard-line positions on social policy and his views of executive power and nationalism that rattle pillars of Western democratic governance.

The biggest challenge facing Trump on the electoral battlefield is turning the energy of his own base into the kind of wave that brings out new voters. While a big part of that will come down to the efficacy of a cutting-edge data operation focused on adding to his base by finding and turning out supporters who don't normally vote, some of it will hinge on the evangelism of people like Moody and Neal who were there for him last time.

In that way, Trump may be his own worst enemy.

Neal said he’s pleased with the economy and having “more of a strong arm” on foreign policy. But the “stupid stuff” Trump says makes it so difficult to advocate effectively on his behalf that Neal doesn’t really try.

"The problem is Trump's whole persona," he said.

Modern history and more recent polling suggest Trump has little margin for error in a nation sharply and bitterly divided in its political loyalties. Like George W. Bush, Trump managed to win a first term while losing the popular vote, and public and private surveys show that he has his work cut out for him if he is to claim victory again.

In the last week, polls from Fox News and Quinnipiac University have shown Trump trailing a series of Democratic rivals — with former Vice President Joe Biden leading by 10 points and 13 points, respectively.

More troubling, at least from a public relations perspective, the recent reporting of internal Trump polling from March by ABC News and The New York Times showed him behind Biden in nearly every important swing state. Biden held double-digit leads in Florida, Michigan, Pennsylvania and Wisconsin — states that collectively account for more than Trump's margin of victory in the Electoral College in 2016 — and NBC reported Sunday that Trump has cut ties to two people who were involved in his polling operations in the aftermath of the data becoming public.

The campaign's top pollster, Tony Fabrizio, said the numbers amounted to a "worst-case scenario" involving a bad turnout model, suggesting they don't reflect the actual state of the race.

The modeling is particularly important when it comes to Trump because his strategy is necessarily built around changing the set of people who show up to the polls in 2020 — and he'll be trying to do that at the same time as Democrats are working to counter him both with a surge of their own and by locking down past Trump voters who have been turned off by his presidency to this point.

Trump's approval rating has been in negative territory for almost the entirety of his presidency, and the most recent tabulation by the number-crunchers at FiveThirtyEight.com pegs it at 42.6 percent.

But his allies say he is in great shape as he gears up for the Orlando rally and the race ahead of him.

"In addition to the standard advantage that incumbents enjoy, President Trump is going to be aided in 2020 by the fact that his first term has been an absolute success — tax cuts and deregulation have resulted in an economic boom, while ISIS has been largely defeated, China is on its heels on trade, and North Korea is not nearly as militaristic as before the president took office," Boris Epshteyn, a former special assistant to Trump in the White House and the chief political commentator for Sinclair Broadcast Group.

"On the flip side, the Democrats are not coming up with any compelling argument as to why the president should not be re-elected," he said in an exchange of text messages with NBC. "The American people are going to judge the president on the merits of his accomplishments, and that judgment will be squarely to his benefit."

Twenty of those Democrats will have an opportunity to make their case against Trump, and for themselves, in the two-night opening debate of the Democratic primary season, which will air on NBC, MSNBC and Telemundo June 26 and 27.

Chris Wilson, a veteran Republican pollster and political data analyst, said he doesn't put much stock in the traditional surveys he's seeing now because they base their turnout models on recent elections — which may not reflect the reality of 2020 if Trump is successful in targeting and turning out new voters.

"I’m very skeptical of any survey today drawing their sample by asking people whether or not they're going to vote," he said. He recently conducted polling, based on voter-data modeling, that showed Trump in much better position in key swing states, including holding small leads in Florida and Wisconsin.

The other factor that's impossible to measure right now is the effect of Trump's campaigning against his eventual Democratic opponent, Wilson said.

"Donald Trump is going to have several months, five or six, to make the nominee entirely unpalatable," he said.

Trump's penchant for personal attack may ultimately rally his own base and depress excitement among Democrats, but there's also a risk that it could have the opposite effect.

After years of Twitter feuds and spoken insults of everyone from world leaders to professional athletes, there's a bit of a social stigma attached to Trump in certain circles that could make it harder for him to reap the benefits of the full-throated support from his army of partisans.

Moreover, the president's comportment can alienate voters who are comfortable with his policies.

While that matters less in Moody's home state of West Virginia and Neal's South Carolina, where Trump is sure to win handily, it could be a significant factor in the handful of swing states that will determine who sits in the Oval Office come January 2021.

Tom Oestreich, 64, of Tucson, Arizona, said in an interview with NBC News that he chose Trump last time because he couldn't vote for Clinton. He would have voted for Biden had he been the Democratic nominee, he said, but he now sees the Democratic front-runner as "tripping" on the campaign trail and "a little bit too old."

A self-described moderate Republican, Oestreich said he is leaning toward Trump because of the state of the economy and his handling of foreign policy but is bothered by what he describes as the president sounding like he has "a fifth grade education." He's giving a second look at Mayor Pete Buttigieg of South Bend, Indiana.

"I’m not crazy about Buttigieg, but he’s got a great pedigree, a great resume," Oestreich said of the Rhodes scholar and Afghanistan War veteran. "If it comes down to the two of them ... there's a very good possibility I could vote for him."

Democrats believe they have a shot at turning Arizona in their favor for the second time since Harry Truman won it in 1948, in part because Trump carried the state by only three-and-a-half percentage points in 2016 and in part because they captured a Senate race there last year for the first time since 1988.

But as has been the case since early in his first presidential run, Trump can count on unflinching support from a loyal base that is more than willing to take on anyone who stands in his way — whether that means Democrats or wavering Republicans. Many of them cast him as their champion in almost epic terms.

"I think he's doing good," Trump voter Kitty Klipstine of Dayton, Ohio, said in an interview for Hardball's "The Deciders," which aired on MSNBC on Monday. "It's just he's fighting Congress, fighting both parties, really, which is a shame because the Republicans should back him all the way."

Like Klipstine, Roger Carey of Ankeny, Iowa, is proud of the job Trump has done and sees any shortcomings as a function of the resistance he's met in Washington.

"I like that he has accomplished the things that he ran on," Carey said. "I like that he wants to support our borders, guarding our borders. Positive things for the country — would like to see Congress back him, though, and get things done."

The trick for the president is to convince anyone who agrees with Carey — but didn't cast a vote for Trump last time around — to back his bid to hold on to the job.

Maura Barrett contributed reporting from Boone, Iowa, and Cal Perry from Dayton, Ohio.