MADISON, Wis. (AP) — More than 37,000 absentee ballots were counted from Wisconsin voters who returned an application form ahead of the November presidential election, a mailing that was a compromise by the politically divided state elections commission.

Democrats wanted to send the mailing to all registered voters, whether they had requested an absentee ballot or not. Republicans on the commission ultimately prevailed in sending the mailing only to 2.6 million people who did not already have an absentee ballot application on file.

It’s impossible to know whether the 37,481 people who returned the application form and later cast an absentee ballot would have done so had they not received the mailing. Wisconsin voters do not register by party, so it’s also impossible to know how many of those voters were Republicans or Democrats.

However, Democrats were more aggressive in promoting absentee voting for Joe Biden while former President Donald Trump and his allies argued against absentee voting, saying before the election that voting by mail was rife with fraud.

Biden won Wisconsin by fewer than 21,000 votes.

After Trump’s loss, he argued unsuccessfully for tossing more than 238,000 absentee ballots that he said were illegally cast in Milwaukee and Dane counties in a failed attempt to overturn Biden’s win. Trump’s arguments were rejected by the Wisconsin Supreme Court and the U.S. Supreme Court. Trump did not single out absentee ballots returned using the application form sent by the Wisconsin Elections Commission.

Some people who received the informational mailing contacted the elections commission to complain, saying they didn’t agree with voters being told how to vote absentee, the commission said in a report prepared for its Wednesday meeting. However, many other calls were supportive, the commission said.

“For many, the mailing provided a source of trusted information about election procedures in an overwhelming and changing environment,” the report said.

In Wisconsin, nearly 2 million people voted absentee in the November election, driven by concerns over the ongoing coronavirus pandemic. That was roughly 60% of the total turnout of almost 3.3 million voters.

While far exceeding the historical average, the total absentee votes cast did not reach the level it did in the April primary early in the pandemic when almost 75% of voters cast ballots absentee.

Of those who voted absentee in November, nearly 41% returned their ballot by mail while 19% returned their ballot at the polls before Election Day, the elections commission said.

The mailer with the absentee ballot application was sent Sept. 1. During the first week after it was sent, more than 25,000 voters registered online and more than 47,000 requested an absentee ballot, the report said.

Ultimately, 40,686 applications using the form from the mailing were approved with absentee ballots sent. Of those, 37,481 were returned and counted, the report said.

Also, of the 2.6 million mailings, 231,533 were returned as undeliverable. The commission explains in its report that this is partly due to the fact that the commission directed that the letter not be forwarded. There are several reasons why the Postal Service can’t deliver mail to an address, including if a person had moved, the address is not an exact match or incorrect.

Of the undelivered letters, 41% of the voters did not participate in the presidential election, the report said. The majority, 57%, did vote. Of that group of 132,293 voters, more than 100,000 of them registered at a new address before voting, the report said.