President Trump on Wednesday escalated his campaign to discredit the integrity of mail balloting, threatening to “hold up” federal funding to Michigan and Nevada in response to the states’ plans to increase voting by mail to reduce the public’s exposure to the coronavirus.

Without evidence, Trump called the two states’ plans “illegal,” and he incorrectly claimed that Michigan’s “rogue” secretary of state is planning to mail ballots to all voters. The state is planning to send applications for mail-in ballots to all voters — not ballots themselves.

“This was done illegally and without authorization by a rogue Secretary of State,” Trump tweeted about Michigan. “I will ask to hold up funding to Michigan if they want to go down this Voter Fraud path!”

Trump later corrected the error and suggested he would not need to withhold federal money, but he did not retreat from his claim that both states are taking steps that will encourage voter fraud. A spokesman for the Trump campaign asserted that the Michigan secretary of state did not have legal authority to send ballot applications to all voters, a claim that she disputed.

Speaking to reporters later at the White House, the president claimed without proof that mail-in ballots lead to “forgeries” and “thousands and thousands of fake ballots.”

“I think just common sense would tell you that massive manipulation can take place,” he said. “And you do have cases of fraudulent ballots where they actually print them and they give them to people to sign, maybe the same person signs them with different writing, different pens. I don’t know. It’s a lot of things can happen.”

The president’s aggressive and unfounded rhetoric drew immediate rebukes from Democrats and voting rights activists, who accused Trump of intentionally sowing mistrust in U.S. elections.

And his claims that absentee voting will encourage cheating are at odds with the activity of state and national GOP leaders, who are mounting aggressive field operations, including mass mailings of ballot applications, to encourage their voters to cast ballots by mail. GOP officeholders in various states — including Nevada — are also backing expansions of absentee voting because of the pandemic.

Trump’s latest attacks show how voting access has become a major battleground in the 2020 presidential race, as both parties invest tens of millions of dollars into dozens of lawsuits and voter outreach across the country to try to shape how ballots will be cast amid the coronavirus outbreak.

Democratic strategists pointed to Trump’s tweets targeting battleground or Democratic-controlled states as evidence that he is trying to gain an edge in states that could decide the outcome in November. They noted that many Republican states are similarly expanding mail balloting, yet Trump has not criticized them.

“They’re doing this because they think it gives them some sort of political advantage,” said Guy Cecil, a former aide to Hillary Clinton who leads the Democratic super PAC Priorities USA Action. “They see what Trump’s poll numbers are, and their philosophy is simple: ‘If we can’t win with the electorate we have, then we try to create an environment that gives us an electorate that we can win with.’ ”

White House press secretary Kayleigh McEnany said Trump is simply trying to prevent voting fraud. “The president is right to look at this,” she told reporters. “We want a free and fair election, and that’s a fair concern.”

Trump has repeatedly railed against mail-in voting, asserting with scant evidence that it is subject to widespread fraud and has hurt Republicans in previous elections. Multiple studies have shown that Republicans and Democrats both can benefit with increased mail-in voting. Cases of ballot fraud are rare.

Trump himself voted absentee in Florida’s primary in March, saying he did so “because I’m allowed to,” adding that he was at the White House and out of state.

Republican officeholders in at least 16 states that do not have all-mail elections have encouraged people to vote absentee during the coronavirus pandemic, according to a tally last month by The Washington Post.

The Trump campaign itself is encouraging supporters to request absentee ballots, such as in an email sent to Pennsylvania voters Wednesday that urged them to “request your ballot and cast your vote from your own home.”

Spokesman Tim Murtaugh said that the campaign is against mailing all voters ballots because it could lead to fraud, but “it is responsible to advise our voters of what the laws are in their states.”

Still, even as they encourage mail balloting among their own voters, a number of GOP organizations, including state parties, the Republican National Committee and conservative-backed independent groups, have followed Trump’s lead in accusing Democrats of encouraging fraud and seeking to put restrictions on mail voting. The RNC alone has committed $20 million to fight liberal-backed lawsuits seeking easier electoral access.

All of it has forced state and national Republicans, and even Trump’s own political operation, to navigate messy and conflicting strategies as they try to balance the president’s distaste for mail balloting with the on-the-ground objective to help their own voters cast ballots during the pandemic.

“We have been clear that we cannot have rogue state officials or activist courts making unilateral decisions,” said RNC press secretary Mandi Merritt. “We continue to support lawful absentee voting with the proper safeguards in place, safeguards which Democrats are suing to eliminate in states like Michigan.”

Trump’s political advisers said he has made clear that he doesn’t like mail balloting and doesn’t want states to expand it.

“He’s not telling us to reverse current rules,” said one senior campaign adviser who spoke on the condition of anonymity to discuss the matter candidly. “He just doesn’t want it expanded or people to use it for other reasons like this. He thinks the more mail voting there is, the more fraud there is.”

Several Trump advisers said they viewed his attacks on Michigan in particular as unwise, given internal GOP polling showing he is trailing in the state. The tweet caught several campaign advisers by surprise, including Republican National Committee chair and former Michigan state party chair Ronna McDaniel, as well as campaign manager Brad Parscale, according to people familiar with their reactions who spoke on the condition of anonymity to describe private conversations.

The first version of his tweet that erroneously said Michigan was sending out ballots — rather than ballot applications — was deleted after hours of internal conversations with Trump and others concluded that it was not a good idea, a Republican with knowledge of the discussions said.

Internal campaign polling has consistently shown Trump trailing former vice president Joe Biden in Michigan, people familiar with the polling said. A Fox News poll in mid-April found Biden leading Trump by 49 percent to 41 percent among registered voters there.

Trump took aim at Michigan a day after its secretary of state, Jocelyn Benson, announced a plan to send absentee ballot applications to all of its 7.7 million voters for primary elections in August and general elections in November.

Benson noted in an interview that at least four Republican states — Georgia, Iowa, Nebraska and West Virginia — have decided to send ballot applications to all voters, just as she did. “It is not a partisan issue to ensure that every citizen can vote,” she said. “Our hope is that the misuse of federal funding that’s being threatened is simply that — a threat. It’s certainly illegal to predicate federal funding on a political agenda.”

In his tweet threatening to curtail federal funds, Trump flagged the Treasury Department as well as Russ Vought, the acting head of the White House Office of Management and Budget. He offered no details about what money he would hold up. Later he told reporters that he spoke Wednesday with Michigan Gov. Gretchen Whitmer (D) but said they didn’t discuss the withholding of federal funds, adding, “I don’t think it’s going to be necessary.”

McEnany said Trump’s tweet “was meant to alert OMB, who wanted to be very careful as we send trillions of dollars to states that we keep this important point in mind.”

Several current and former budget officials said the majority of federal assistance for states is distributed according to formulas set by Congress that would be difficult — if not impossible — for the president to unilaterally alter.

Other assistance comes in the form of grants that are awarded jointly by relevant federal agencies and the Office of Management and Budget, which could decide not to award money to Michigan or Nevada. But any political interference with the grant-making process would likely be challenged in court, said William Hoagland, a Republican and former staff director on the Senate Budget Committee. “OMB and the agency head would be legally culpable,” Hoagland said. “If the states apply and meet all the requirements, I think it would create legal challenges.”

Republicans are more united about Trump’s attack on Nevada, which has moved to a largely mail-in system for its June 9 primary. Republican Party leaders have criticized the state for deciding to mail ballots, not just ballot applications, to all active and inactive voters. That could allow bad actors to obtain ballots sent to voters who have moved or died, they argue.

“State of Nevada ‘thinks’ that they can send out illegal vote by mail ballots, creating a great Voter Fraud scenario for the State and the U.S.,” Trump said in his second tweet. “They can’t! If they do, ‘I think’ I can hold up funds to the State. Sorry, but you must not cheat in elections.”

His criticism is complicated by the fact that Nevada’s secretary of state, Barbara Cegavske, is a Republican. A federal judge upheld her decision to mail ballots to all voters in Nevada’s upcoming primary. Democrats are now suing to ensure that in-person voting is also available on Election Day.

Cegavske’s office issued a statement Wednesday defending her decision, noting that “many safeguards” are in place to prevent fraud, including signature requirements and bar code tracking.

The state’s Democratic governor, Steve Sisolak, was more pointed in a tweet Wednesday: “For the President to threaten federal funding in the midst of a pandemic over a state exercising its authority to run elections in a safe and legal manner is inappropriate and outrageous.”

Colby Itkowitz, Annie Linskey and Scott Clement contributed to this report.