Hawaii officials say they plan to follow state law requiring mail-in voting this year while lawsuits proceed over President Donald Trump’s executive order that critics say would give the federal government unprecedented control over U.S. elections despite the Constitution’s guarantee that Congress and each state hold that authority.

State Attorney General Anne Lopez announced April 3 that Hawaii had joined a coalition of 19 attorneys general in suing Trump in U.S. District Court in Massachusetts, saying his executive order is clearly unconstitutional and would impose new requirements, including proof of U.S. citizenship in order to register to vote.

They argue the order could lead to a national database that could be used for immigration enforcement, cause fear in state election officials and sow chaos and uncertainty that could have a chilling effect on states like Hawaii with strong histories of immigration.

“We think it’s a piece of a larger effort to try to reduce the number of people voting that will chill the right to vote,” said Emily Hills, senior staff attorney for the Hawaii chapter of the American Civil Liberties Union.

Lopez said in a statement that Hawaii joined the lawsuits challenging Trump’s executive order, in part, because it “intrudes on Congress’ and the states’ power over elections. This unlawful effort to usurp election authority will irreparably harm the states and interfere with the lawful exercise of the right to vote.”

The order also requires states to rewrite their ballot-counting laws to exclude absentee or mail-in ballots received after Election Day. In Hawaii, ballots must be received by county election officials before voting ends at 7 p.m. on Election Day in order to be counted.

In the November 2024 presidential election, 860,868 island residents registered to vote and 61% turned in ballots.

Out of the 522,236 residents who voted, 92.5% — or 483,078 — cast their ballots by mail compared with 7.5% — or 39,158 — who voted in person at polling centers.

Even so, in-person voters inundated balloting locations on all islands on Election Day, delaying the first return of results for hours. Trump has encouraged his supporters to not trust mail-in balloting and early in-person voting, calling on them to turn out on Election Day instead.

Hawaii voters in 2024 overwhelmingly voted for former Vice President Kamala Harris over Trump, who gained only 37% of votes cast statewide compared to Harris, who won 60% but lost nationally.

Since then, the Trump administration has persuaded the U.S. Supreme Court to fast-track multiple cases, leading supporters of Hawaii’s mail-in voting to worry the court could decide in Trump’s favor ahead of the state’s Aug. 8 party primaries or Nov. 3 general election.

“It does seem like the United States Supreme Court has been expediting things at the government’s request,” Hills said. “Certainly anything on the eve of an election would be very, very difficult for states, not just Hawaii, to be able to cope with.”

Hills declined to speculate whether the Supreme Court will hear arguments — or make a ruling — ahead of either Hawaii’s primary or general elections.

“I’ve been surprised before,” Hills said. “So, I’m really not making any predictions. I don’t always see eye-to-eye with the way the current Supreme Court rules on things. But I completely sympathize with the state for not wanting to put time and energy and money into contingency plans because that’s time and energy and money that could go to other places.”

Concerns over Trump’s mail-in executive order increased after the Supreme Court last month gutted the Voting Rights Act by excluding race as a factor in drawing political districts.

The Brennan Center for Justice at NYU Law also joined the lawsuit challenging Trump’s mail-in voting executive order, saying it directs the U.S. Postal Service to determine who may vote by mail. It gives the Postal Service the power to “refuse to deliver ballots sent by anyone not included on newly created federal mail voter lists,” according to the nonpartisan Brennan Center. “It threatens criminal penalties for election officials, mail carriers, and others who send ballots to or deliver ballots from individuals the administration deems ineligible.

“Far from improving elections, this executive order would create chaos for election officials, erode public confidence in our elections, and block Americans from exercising their most fundamental right and responsibility as citizens — voting,” Brennan Center officials said.

For now, state Elections Officer Scott Nago said there are no backup plans for Hawaii to change course on mail-in voting ahead of any potential ruling by the Supreme Court.

“We still have laws we have to follow, which is the state law,” Nago said. “So we can’t just change without any change to the law.”

Colin Moore, who teaches public policy at the University of Hawaii, called Trump’s executive order “a violation of the Constitution that says that only states and Congress have control over federal elections. The president has no role. The Constitution is pretty clear that this is not a power granted to the president.”

He agreed that Trump’s mail-in directive is part of a larger effort to take control of states’ voter registration data while intimidating state elections officers across the country.

Mail-in voting was originally pushed in the 1990s by Republicans in Oregon to “help voters get their votes in, which would help Republicans in Oregon,” Moore said.

The push for mail-in voting spread to become a bipartisan issue with both Democrats and Republicans arguing it makes it easier for voters in rural communities to cast their ballots.

Then, Moore said, “Trump got involved and started making these baseless claims that all mail voting is full of fraud or that noncitizens are voting, none of which has ever been proven.

“No one has found widespread voter fraud in the way that Trump alleges,” he said. “The irony here is that vote-by-mail is extremely popular nearly everywhere it exists.”