CNN  — 

Republican officials throughout the country are reacting with growing alarm to President Donald Trump’s attacks on mail-in ballots, saying his unsubstantiated claims of mass voting fraud are already corroding the views of GOP voters, who may ultimately choose not to vote at all if they can’t make it to the polls come November.

Behind the scenes, top Republicans are urging senior Trump campaign officials to press the President to change his messaging and embrace mail-in voting, warning that the party could lose the battle for control of Congress and the White House if he doesn’t change his tune, according to multiple GOP sources. Trump officials, sources said, are fully aware of the concerns.

The impact could be detrimental to the GOP up and down the ticket, according to a bevy of Republican election officials, field operatives, pollsters and lawmakers who are watching the matter closely. Every vote will count in critical battleground states, they argue, fearful that deterring GOP voters from choosing a convenient option to cast their ballots could ultimately sway the outcome of races that are decided by a couple of percentage points.

And with the coronavirus pandemic potentially bound to get worse in the fall, voting by mail is becoming an increasingly popular option since many voters may prefer not to wait in long lines at polling stations. That will leave Democrats with a major advantage if their voters send their ballots by mail while Republican voters forgo that option simply because they are listening to the concerns of the President.

In Wisconsin, a state that was central to Trump’s narrow 2016 victory, Republicans were “begging our voters” to vote absentee when the pandemic first hit, said Rohn Bishop, Republican Party chairman in Fond du Lac County, where Trump will need to drive up GOP turnout in November.

“Then the President has some tweets and gets upset with mail-in balloting and we dropped the issue like a hot potato, and that’s where I think we’re making a mistake,” Bishop said. “Our voters are running away from it. That kind of terrifies me.”

Bishop added bluntly: “I’m getting aggravated because I think we’re only hurting ourselves. … Anything that ties an arm behind my back, I don’t like that.”

Bishop’s concerns are shared by Republican officials at the county and state level – as well as ones who are deeply involved with the national party.

Glen Bolger, a top Republican pollster, told CNN he had just surveyed a battleground state and found that three-quarters of voters who plan to vote by mail or absentee vote intend to support former Vice President Joe Biden; just 15% of mail-in voters in that survey planned to use the mail option to vote for Trump. Bolger declined to name the state, but said it exemplified the real problems for Republicans if the trend continues.

“It could have a corrosive impact if some voters who would have voted don’t get to vote on Election Day – a bunch of votes would have been left on the table,” Bolger said. “If he changed his message on this, he could have a positive impact,” referring to Trump.

Former Pennsylvania Gov. Tom Ridge, a Republican who was a Cabinet secretary under President George W. Bush, said discouraging mail-in voting is “very perilous for the Republican Party” and puts his party at “an incredible disadvantage.”

“There’s no inherent advantage to one party or the other,” said Ridge, who chairs the bipartisan group VoteSafe, which advocates for expanded voting access. “The advantage goes to the party that utilizes that method – that option of maximizing participation – on Election Day. So if you have a Republican President undermining his own base, and suggesting they don’t use absentee ballots, while the Democrats have demonstrated, particularly thus far in the primary season, they understand its value … then he puts his own party as a decided disadvantage because it discourages Republicans from using it.”

And Republicans, too, are concerned that Trump’s criticism of the process could cast doubt on the integrity of the election, particularly in closely contested states like Ohio.

“It is irresponsible – whether it’s a Republican or Democrat – for people to create a sense, incorrectly, in the minds of voters that they can’t trust their elections,” said Ohio Secretary of State Frank LaRose, a Republican, referring to both the President’s claims and Biden’s recent suggestion that Trump might not leave office if he loses.

In Ohio, nearly 8 million registered voters will get absentee ballot requests after Labor Day, and LaRose predicts that roughly 35%-40% of the ballots will ultimately come by mail in November, up from roughly 20%-25% in past elections, amounting to the “highest level of vote-by-mail that we’ve ever seen in our state’s history.”

“When people try to say that voting by mail or absentee mailing benefits one party – it just doesn’t bear out in Ohio. People want to vote,” LaRose said. But asked if fewer Republican voters may choose to vote absentee in November because of the President’s criticisms, he said: “That’s absolutely a possibility.”

GOP leaders in the House and Senate have publicly and privately called for more resources for mail-in voting – and hope the President changes his tune.

“A lot of people are going to vote by mail, and we need to do what we can to both see that is done safely and encourage people to believe and ensure people that it is going to be done safely,” Senate Rules Chairman Roy Blunt, a Missouri Republican, said Thursday.

New York’s 27th Congressional District special election last month illustrated the potential dangers for Republicans if their voters swear off mail-in voting. The state, which has several closely contested House races, expanded mail-in voting this year after Democratic Gov. Andrew Cuomo signed an executive order in April to mail all residents applications for absentee ballots.

In the solidly Republican district, GOP state Sen. Chris Jacobs was leading Democrat Nate McMurray 64%-27% after election night – but before absentee ballots were counted, according to the state’s unofficial results. After the district’s absentee ballots were tallied, the margin shrank to 55%-44%.

Trump tries to make a distinction over mailed ballots

Republicans on Capitol Hill, worry the trend will continue if Trump keeps up his rhetoric, have tried to push the President to change his message. Sources said the issue has been raised repeatedly with Trump campaign officials, who have acknowledged the potential problems for the GOP.

After prodding from campaign officials, the President has tried to massage his messaging in recent days. Indeed, campaign officials were successful in getting him to try to make a distinction during his speech in the White House Rose Garden on Tuesday evening. Trump argued that it’s perfectly acceptable for voters to request absentee ballots. But he argued that states that proactively send out ballots to voters are creating a system rife with fraud.

“You’ll have tremendous fraud if you do these mail-in ballots,” Trump told reporters. “Now, absentee ballots are OK, because absentee ballots – you have to get applications. You have to go through a process.”

Trump has been railing about mail-in voting for months as states expand vote-by-mail options, repeating numerous false claims about voter fraud. There’s no widespread fraud in US elections.

Absentee voting, of course, is conducted by mail, and experts say Trump is creating a distinction where none exists. It’s true that some states require voters to request absentee ballots, and some require voters to have excuses for absentee ballots, while others do not. And some states require ballots to be sent unsolicited to all registered voters.

But in every case, the ballots are returned the same way: through the mail.

Asked if most voters would understand the distinction Trump is trying to make between absentee ballots and ones sent proactively in the mail, Matt Mashburn, who serves on Georgia’s State Elections Board, said: “No.” He added: “I think Georgia has a wise system.”

The June primary in Georgia saw an explosion of interest in absentee ballots in a state where voters must request absentee ballots after their applications are verified and their signatures are matched by county officials.

In typical Georgia elections, about 5% of ballots are returned by absentee; in the June primary, however, roughly 49% of the ballots were absentee – which amounted to 1.15 million, according to Gabriel Sterling, who is the statewide voting implementation manager in Georgia. Democrats outpaced Republicans on absentee voting, but they had a competitive Senate primary, which the GOP did not.

“There is a weaponizing of election administration from the left and right – and it’s not helpful to how elections are supposed to run,” Sterling said, referring to concerns from Democrats about voter suppression and from Republicans about claims of voter fraud.

And as Trump tries to make a distinction between ballots mailed proactively and absentee ballots, voters “probably” don’t see much of a difference, Sterling said.

“Most people think voting is voting,” he said.

While Trump has claimed that vote-by-mail will be a disaster for Republicans, recent election results suggest that’s not necessarily the case. In California’s 25th District, a special election to fill former Democratic Rep. Katie Hill’s seat was conducted almost entirely by mail, with Republican Mike Garcia easily winning the seat over Democrat Christ Smith, 54%-46%.

Still, Republican legislators in states across the country are introducing bills to limit mail-in voting in November. And lawsuits have emerged as well.

LaRose, the Ohio secretary of state, has wanted to make it even easier to request absentee ballots by allowing voters to go online and request them – rather than doing it by mail. But he has faced opposition in the state Legislature, and he said the President’s criticism of the process is “a factor.”

In Florida, Democrats held a 300,000-voter advantage last month in the number of people who had applied to vote by mail.

“It just means that we have work to do, and we’re going to do the work and we’ll take care of it,” said Dean Black, chairman of the Republican Party in Duval County, which encompasses Jacksonville. “Historically, vote-by-mail works in Republicans’ favor. And so that would tend to be a net positive for President Trump.”

CNN’s Kaitlan Collins and Marshall Cohen contributed to this report.