“The thinking among Democrats was that Republicans would be better at it than we were, that they’d outthink and outspend us,” Senator Ron Wyden, Democrat of Oregon, said.
When Senator Bob Packwood, Republican of Oregon, resigned amid a sexual harassment scandal a year later, Mr. Keisling, a Democrat, made the special election to replace him a mail-in contest because, he said, “if I didn’t, I was going to get thrown out of town by all the people who loved it.” Mr. Wyden won that race.
Oregon voters adopted mail voting statewide in a 1998 ballot measure, with 70 percent embracing it.
Vote by mail’s original story was similarly bipartisan in Washington. Republican lawmakers and county election officials pushed to expand absentee balloting to help rural voters, and state lawmakers granted everyone the right to ask for a mail-in ballot in 1974. A Republican county auditor, Sam Reed, held the first all-mail primary in 1993 and championed the push for statewide mail voting when he became secretary of state in 2001. State leaders transitioned fully to mail-in ballots in 2011, when most in Washington were already choosing it.
Studies have found that mail-in balloting increases participation, with scant evidence of fraud.
“You can suppress the vote in so many ways on Election Day,” said Oregon’s junior Democratic senator, Jeff Merkley. “Vote by mail removes most of those options.”
The biggest controversy in the Northwest came in 2024, when Oregon discovered that its Department of Motor Vehicles had mistakenly registered about 1,600 people who had not provided proof of U.S. citizenship. State officials later said about a dozen actually cast ballots.
Dennis Richardson, Oregon’s Republican secretary of state during the early years of the first Trump administration, warned the president that unsupported allegations against mail voting risked undermining public trust. Kim Wyman, a Republican who held the same job in Washington for nearly a decade, urged critics within her party to follow the evidence rather than repeat unsupported claims of fraud.
Those requests have gone unheeded, as the Trump administration cuts funding to guard against election cyberattacks, presses states to turn over voter rolls and pushes to make potential voters show proof of citizenship.
All of those steps are seen as attacks on mail voting in particular because they add logistical hurdles to easily registering people to receive mailed ballots. Oregon, for example, automatically registers people to vote when they obtain a driver’s license. There’s no county election office to visit or additional paperwork to mail.
The goal of conservative cuts and challenges, said Tobias Read, a Democrat and Oregon’s current secretary of state, “is to put strain on the system, to add steps, to add inconvenience and holdups.”
Last week, the president issued a new executive order that would force vote-by-mail states to stop automatically sending ballots to all registered voters. Instead, the president wants the Postal Service to vet the list of people receiving ballots and impose requirements on ballot envelopes and how they’re tracked. Mr. Trump said the order was meant to “stop the massive cheating that is going on.”
Oregon’s Democratic attorney general, Dan Rayfield, said the president simply fears his party will lose in November. Republicans, Mr. Rayfield said, “aren’t even pretending right now.”
Leaders in Oregon and Washington have responded to all this with a series of lawsuits, including one filed last week arguing that the president’s latest executive order illegally intrudes on state authority to oversee elections.
So far, the states are winning. But Mr. Holmes expects anti-mail-balloting efforts in the legislature to continue, despite their long odds for success, because, he said, even failed attempts undermine confidence in election results and help losing candidates justify refusing to concede.
Oregon’s senators said worries about the fate of voting by mail had, along with the war in Iran, dominated what they had heard from constituents at recent town halls.
“People here are very, very worried about the future of this system they pioneered,” Mr. Merkley said, “as they should be.”
Anna Griffin is the Pacific Northwest bureau chief for The Times, leading coverage of Washington, Idaho, Alaska, Montana and Oregon.