A few pertinent details:
The Governor and the Senate/House are NOT the same party. Governor is Dem, Sen/House both Republican.
The Governor stated many times pre-election, with confirmation from legal, that changing the date would result in nothing more than a court fight. There was no possible way the WI State Supreme Court was going to let this go through.
However, up until the DAY BEFORE the election, we (the voters of WI) were going to be allowed a later date for the by-mail ballots to be collected and counted (almost a week more). This had come from an appellate court that said there was no mechanism to change the date of the election, but the court did allow the extended timeline for absentee ballots. The Republican Senate/House fought the Democratic Governor's executive order to delay the election until June in the WI Supreme Court. This new struck down the DAY BEFORE the election. Also the day before the US Supreme Court struck down the extension date for the absentee ballots. This was HUGELY important because our various state offices had been inundated with absentee ballots because of Covid 19. I'm talking hundreds of thousands more than is usual. WI citizens did not want to vote in person!
In addition to that mess, there were thousands of poll workers not willing to work. Without poll workers you can't have as many polling places. And all those hundreds of thousands of people who had applied for the absentee ballots, who had their absentee ballots, but no longer trusted the system because of the back-and-forth that been going on for weeks, wanted to vote on election day rather than take a chance that their ballot wouldn't be received in time to be counted. Myself included. So, we all showed up at the polls... the greatly reduced number of polls...
The Governor called a special session the weekend before the election, but it was immediately gaveled closed. He tried to work with the other side and they would not even discuss the matter. And his legal team was correct - him signing an executive order would simply get thrown out in court. The appellate court had already said there was no mechanism to change the date.
So, as I said - a cluster. But this can not be put on the Governor's head. The only way this election could have been delayed is if the Republican Senate and House would have agreed to the change. They wouldn't even attend the special session.