COLUMBUS, Ohio -- During a recent phone conversation, Ohio GOP chairman Matt Borges told Donald Trump he was encouraged by the fact that Republicans have added more than a million new voters to their state's ranks since the presidential primary.

"Is that because of me?" Trump asked.

Borges' simple answer: "Yes."

He's got to hope so.

Ohio doesn't formerly register voters, but accounts for them by how they choose to participate in primaries. On March 15, just over a million independents and Democrats crossed over to cast ballots in the Republican race, handing the GOP an 820,000 voter affiliation advantage heading into the fall.

Once these voters grab November ballots, there's no telling if they'll revert back to their prior preference. But Trump's going to need nearly all of these newbies in order to carry the Buckeye State against Democrat Hillary Clinton.

Despite losing the state's primary in March by 11 points, having failed to secure the endorsement of its popular governor and his former rival, John Kasich , and playing catch-up organizationally to Clinton's operation, the presumptive GOP nominee begins the summer within striking distance in Ohio.

A survey taken last week by the new bipartisan polling firm Raba Research found Clinton clinging to a 3-point lead over Trump here that falls inside the margin of error, 41 percent to 38 percent.

Trump made his first general election campaign visit to Ohio June 28, just days after he enlisted a state campaign director and following three visits by Clinton in the last three weeks.

While the Trump team has not set up a formal office in the state yet, the Republican National Committee has dispatched 55 staffers to jumpstart the get-out-the-vote operation, which will go into high gear during the week of the national convention in Cleveland.

"They kind of get a little annoyed because everyone wants to go to the convention. But the truth is their most effective use for us is to be in the field, talking to volunteers and making voter contacts," says Borges. "We've always had our highest number of voter contacts the week of the convention."

Many of those contacts will involve following up with the newly affiliated Republican voters who came out in record numbers to participate in the GOP presidential primary.

Even finishing second to the home-state son Kasich, Trump drew 727,585 votes -- still about 48,000 more than Clinton, who easily defeated Bernie Sanders in the Democratic primary.

"It's not like they didn't have a contested race on their side, they did," Borges says.

Ohio voters think Clinton's "full of sh-t, they don't like her," he swipes.

But the Clinton campaign knows a lot of voters who don't like Trump, either. Reminding them of his most polarizing statements and proposals -- building a border wall, banning Muslims, degrading women -- will be key to their formula to keep Ohio in the Democratic column for a third consecutive presidential race. To counter his appeal to working class families, the Clinton campaign will raise Trump's more unscrupulous business deals to convey that he got rich on the backs of working people.

"Voters across the spectrum continue to reject Donald Trump as president because they know he's unfit, unqualified and too dangerous," says Chris Wyant, Clinton's Ohio campaign director.

It's been argued that the Cincinnati area was responsible for the reelection of the last Republican president, George W. Bush. In 2004, Bush banked a 160,000 vote lead over John Kerry in the five counties around Cincinnati, including notching a 6-point win in Hamilton County. It was enough to weather severe losses in Cleveland and Bush won the state, clinching his re-election.

In 2008, candidate Barack Obama flipped Hamilton County, taking it by 5 points to help him secure the Ohio. In 2012, he repeated his performance there.

Even Republicans expect Clinton to carry Hamilton this year. What will be more hotly contested are the counties bordering it, populated by suburban families with married college-educated females inclined to vote Republican but are wary of Trump.

The Clinton campaign also points out that even Borges acknowledged back in March, that it was partly loyalty to Kasich that pushed so many Democrats and independents over into the GOP primary. Another prime driver, they say, was fear of Trump's ascendance.

A new Republican political action committee, started by former Kasich aides, has been formed to help Sen. Rob Portman communicate with 300,000 of these new voters. The official party won't be able to reach them, Jeff Polesovsky, Kasich's former political director told the Cincinnati Enquirer , because "of the voters' cool feelings toward Trump."

Still, with its manufacturing losses, skepticism of free trade, coal industry jobs and pockets of rural angst in Appalachia, Trump appears better situated in Ohio than other battlegrounds with more diverse demographics.

But the private fears of Republican officials here are that if Clinton eventually carves out formidable leads in other battleground states like Florida and Virginia, the momentum of inevitability will be strong enough to carry her in Ohio.

"I think it is very tight here right now. I think we will be able to build out eventually," says a Clinton Ohio adviser.

And if Trump sustains significant losses in the population centers of Cincinnati, Columbus and Cleveland, even supercharged turnout on his behalf in outstate counties likely won't be enough to close the deficit.

"He's going to absolutely have to drive numbers in Republican parts of the state. We really really have to drive them really high," says Borges.

Kasich, the person who could be most helpful to Trump here remains on the sidelines, with no plans to endorse or campaign with the likely nominee unless he drastically changes his tone.

"It's the conduct of the campaign. You can't erase what's been done or said up through a few days ago," says John Weaver, Kasich's campaign strategist. "Nobody's throwing marbles under their feet. We're not putting up roadblocks. It's really up to him about the campaign he runs. Fix your damn personal negatives."

Borges would certainly like to see Kasich stamp Trump with his sterling homestate popularity.

"I'd love to see that occur. I'm going to hope that they start coming closer to where they need to be so that the governor feels comfortable," he says.

Because Trump also conceded something else in his recent phone call with Borges.