MADISON, Wis. (AP) — More than 97,000 people in Wisconsin cast absentee ballots in person on the first day they could, leading to long waits at some polling sites that were made worse by an overwhelmed computer system that clerks use to process ballots.

Republicans and Democrats have been pushing voters to cast ballots early, leading to the surge and reports of people waiting in line for hours at clerks’ offices and other polling places around the state Tuesday.

The Wisconsin Elections Commission reported Wednesday that 97,436 people voted in-person on Tuesday. That is up from 79,774 who cast ballots on opening day of in-person voting in 2020. However, due to the COVID-19 pandemic that year, in-person voting numbers were down while absentee voting by mail was higher.

As of Wednesday, 475,460 absentee ballots had been returned, including those sent by mail and cast in person. That is less than half of the more than 1 million that had been returned by that point four years ago.

There are more than 3.5 million registered voters in Wisconsin, but voters can register and vote on Election Day.

The larger-than-expected outpouring of voters Tuesday caused a slowdown of the WisVote system that some clerks use to print a label that is placed on the outside of an in-person absentee ballot, said the elections commission, which noted that staff worked quickly to increase system capacity.

The problem persisted on Wednesday and appeared to be affecting non-election related state systems as well, the commission said.

“High levels of in-person absentee voting do still appear to be compounding the issue,” it said.

Ann Jacobs, the commission’s Democratic chair, put a positive spin on the delay, calling the large turnout that resulted in the problem “terrific.”

“Lots of people came out,” Jacobs said. “The system slowed, it never went all the way down but it did slow quite a bit, we’re pretty confident it won’t happen again.”

Scott McDonell, the Dane County clerk, said he wasn’t surprised by the high level of first-day voters given that it has also happened in other states this year.

Wisconsin is one of a small number of battleground states where the race between Vice President Kamala Harris and former President Donald Trump could go either way. That has resulted in massive spending by both sides in the state, encouragement to vote early, and numerous visits from the candidates and their surrogates.

“These were all the voters who had their mind made up for some time,” McDonell said. “I think we saw across the state more Republicans voting early, which is a good thing. There shouldn’t be a difference in how people vote.”

Voters in Wisconsin don’t register by party, so it’s impossible to know how many Republicans and Democrats have returned ballots so far.

McDonell predicted that turnout will be high for a couple of days and then slow down. He recommended that voters wait a couple of days to vote in person.