Both Democratic front-runner Hillary Clinton and rival Bernie Sanders vowed to tackle problems important to Americans in Appalachia on April 26, after voters in Maryland, Pennsylvania, Connecticut, Delaware and Rhode Island went to the polls. (Sarah Parnass/The Washington Post)

As Hillary Clinton increasingly turns her attention to a general election against Donald Trump or Sen. Ted Cruz, her campaign and fellow Democrats have begun in earnest to bolster staff and campaign organizations in key battleground states.

In Virginia, Ohio and Florida — the three biggest swing states in the last election — the Clinton campaign is teaming up with state and national Democratic organizations to build voter files, organize thousands of volunteers, register tens of thousands of voters and raise the funds necessary to compete against a Republican opponent.

And in the first concrete sign that Clinton’s general-election effort has gone beyond planning, the Democratic National Committee has begun transferring money raised jointly with the Clinton campaign to state committees to help fund the effort, according to Democrats with knowledge of the financial strategy.

In Ohio, the party has doubled the number of staffers to 60, according to state Democratic Party chairman David Pepper, a number that is expected to grow considerably in the coming weeks and months.

In Virginia, national leaders are holding weekly conference calls with congressional campaigns to coordinate staff and volunteers and avoid overlapping efforts.

In Florida, Democrats have been registering voters at a rate of 2,000 to 3,000 a month this year, slightly exceeding the registration rate during the same period in 2008.

All told, the 2016 general-election effort is expected to meet or exceed the more than 1,000 staffers deployed by President Obama in those three states in 2012, campaign and party operatives said.

“We’re going to have a pretty good head start on the other guys,” said Scott Arceneaux, executive director of the Florida Democratic Party.

Republicans disputed that, arguing that they are ahead by many measures — and that national Democrats are playing catch-up to a years-long effort by the Republican National Committee to build a state-by-state organization after two consecutive presidential defeats in 2008 and 2012.

But the GOP remains mired in a divisive primary battle that will drag on at least into June, if not through the party’s convention in late July. That has stalled the ability of party leaders to organize in swing states in conjunction with a presumptive nominee.

And the GOP’s work could be further hindered if the nomination is claimed by Trump, who is opposed by many state Republican leaders and has dedicated minimal energy to local organizing.

Republican operatives insisted they have an organizational advantage, however. After establishing what they call a “permanent ground game” following their defeats in the past two presidential elections, the national and state parties have focused intensely on building an apparatus to identify, register and turn out voters, several operatives said.

Donald Trump vs. Hillary Clinton on the issues

In Florida, for instance, GOP registration has increased by 100,000 voters this year — although much of that is attributed to primary enthusiasm and not the organizational efforts of the party. There and in North Carolina, Republican registration exceeds that of Democrats, said RNC spokesman Ryan Mahoney. All told, across seven battleground states, party officials have taken credit for registering more than 20,000 voters.

“The RNC has never been more prepared for a general election,” Mahoney said.

In addition, in conjunction with state parties, Republicans have installed just over two dozen paid staffers in Ohio and Virginia and 30 paid staffers in Florida.

Meanwhile, dozens of Democratic officials said in interviews that they are so confident about the prospect of taking on Trump or Cruz (R-Tex.) that they are pondering a dramatic expansion their ambitions for 2016.

“We’re almost pinching ourselves, like, ‘Oh my God, is this really happening?’ ” said Rep. Gerald E. Connolly (D-Va.), who represents a Democrat-rich swath of the Washington suburbs. “There is some probability of a comprehensive Democratic victory and Republican defeat.”

“Democrats have to start thinking beyond the normal boundaries here,” Connolly added.

In Florida in 2012, Obama’s campaign registered more than 350,000 voters — four times Obama’s victory margin over Mitt Romney on election night, according to Ashley Walker, who ran Obama’s reelection efforts in the state that year.

With Democrats already on pace to exceed that number — and with the biggest months of voter registration still ahead — Democrats are optimistic that, in the end, their effort will swamp that of Republicans, despite the GOP’s enthusiasm advantage during primary season. Said Walker: “This entire state is about the margins: How much will Democrats lose Marion County by? How much will we lose Duval County? How much we win Miami-Dade by.”

Democrats in Ohio acknowledged that Trump has demonstrated some strength in parts of the state where his stance on trade has resonated.

“If you look at the Republican primary, Donald Trump carried all of eastern Ohio against [John] Kasich, a governor who had an approval rating in the 60s among Republicans,” said Dayton Mayor Nan Whaley, a Democrat. “He came within 5,000 votes in my county. That had everything to do with trade.”

Republicans also said that Clinton’s weak favorability ratings, particularly when it comes to the issue of trust, will give them an opening. Bob Sutton, chairman of the Broward County GOP Executive Committee in Florida, suggested that in particular the FBI investigation into Clinton’s use of a personal email server could pose problems for her.

“If our federal laws were enforced, I would feel more confident,” Sutton said. “That would definitely take Hillary out.”

Clinton is expected to begin general-election-focused travel in the coming days, including trips to Ohio, Michigan and Florida.

She has also begun using funds raised through a joint fundraising committee as a mechanism to begin coordinating with state parties and down-ballot Democratic campaigns to put in place coordinated field programs. The joint fundraising committee, called the Hillary Victory Fund, raised $60 million through the end of March for the Clinton campaign, the Democratic National Committee and 32 state party committees.

According to Federal Election Commission reports through the end of March, the fund has transferred $5.8 million to the DNC since the start of the election cycle. In April, the joint committee transferred an additional $2.5 million to the DNC, according to Democrats with knowledge of the transaction.

The national committee is also preparing to transfer funds to state parties in Ohio, Florida and Virginia — $200,000 apiece — to finance the salaries of field organizers in those states.

The Democrats’ efforts will be particularly targeted at young voters, African Americans, Latinos and women. Trump’s comment after his sweep of the five East Coast primaries Tuesday — that “if Hillary Clinton were a man, I don’t think she’d get 5 percent of the vote” — will only fuel those efforts.

“The Republicans really are hellbent on building our coalition,” said one Democratic operative in Virginia who spoke on the condition of anonymity to discuss campaign strategy candidly, noting specifically the advantage Democrats will have attracting the support of minorities. “With their rhetoric, they are seriously damaging their ability to make a credible case for why any voter of color should vote for a Republican.”

Latino voters in Florida will also be a top priority. According to Clinton’s allies, the slate of Republican candidates has given their camp unprecedented “ammunition.”

“I see people with sound trucks in West Tampa diving around with bullhorns saying, ‘Is this what you want?’ ” said Anna Cruz, a longtime Clinton ally who ran her 2008 Florida campaign. “You know, barriers. We’ve been given so much by these candidates to motivate Hispanic voters.”

Clinton will dispatch Housing and Urban Development secretary and potential vice-presidential pick Julián Castro to Ohio’s Cuyahoga County Democratic Party dinner in June, as a sign of the campaign’s commitment to local fundraising and a signal to the county’s small but growing Latino community that their turnout could make a difference.

Outside groups such as the pro-Clinton super PAC Priorities USA have already committed more than $125 million to bolster the case in battleground states.

Bryan Williams, who is chairman of the Summit County Republican Party in Ohio and supports Kasich, warned that if Trump is the nominee, he will need to make changes.

“I am not blind to the fact that Donald Trump is not fully strong with women,” he said, later adding, “He needs to campaign in a way that allows him to be more appealing to female voters.”

Williams said he is “less confident” than he was at this point in 2012, but “not because of the opposition, because I think we have a Balkanization of interests and positions that is making it harder than ever to unify the party.”