It is the voters who don’t turn out like clockwork, many of whom have weak partisan identities, who can make a crucial difference in close-fought races. Those are the voters some Republicans fear will be lost to the party if mail voting is not embraced.
“The president has his viewpoint and we have ours; we’re trying to win elections,” said Dave Millage, the Republican chair of Scott County in Iowa. He anticipated that mail voting would also be popular in November, when Iowa Republicans will be defending a vulnerable senator, Joni Ernst, as well as trying to flip a congressional seat in the Second District, which includes Scott County.
“We will call everybody to request an absentee ballot and make sure they get them in,” Mr. Millage said. “You bank that vote, you don’t have to spend money to get them out to vote. You can cross them off the list.”
But so far, Mr. Trump’s disparagement of mail voting is winning out in Scott County, which encompasses Davenport. As of Monday, 10,344 Democrats had voted by mail, or 66 percent of the total, compared with 5,342 Republicans. Only 54 percent of county voters who are registered with a party are Democrats. Moreover, Republicans have a contested primary for the open House seat while Democrats do not.
Before Mr. Trump made mail voting toxic to many of his grass-roots supporters, it was widely used in many states, including some in which more Republicans than Democrats tended to vote absentee.
It was Republican majorities in the Pennsylvania Legislature that passed a bill last year expanding no-excuse mail voting to any registered voter. It was signed into law by Gov. Tom Wolf, a Democrat.
Mr. Trump, who has voted by mail in Florida, has weaponized the issue recently as polls showed him falling behind in battleground states. He falsely claimed a Democratic secretary of state in Michigan had “illegally” sent absentee ballot requests for the November election, and he threatened to hold back federal funds to Nevada if its Republican secretary of state went ahead with plans to send mail ballots directly to registered voters before its June 9 primary.