Across most of the battleground states, President Biden’s re-election campaign is trailed by worrisome polling, gripes about a slow ramp-up and Democratic calls to show more urgency to the threat posed by former President Donald J. Trump.

Then there is Wisconsin.

Mr. Biden — who is scheduled to travel to Milwaukee on Wednesday to visit his state campaign headquarters — did not have to rev up a re-election apparatus in Wisconsin. Local Democrats never shut down a vaunted organizing network they built for the 2020 presidential campaign and maintained through the 2022 midterm elections and a 2023 State Supreme Court contest that was the most expensive judicial race in American history.

While in other presidential battlegrounds, Democrats are still trying to explain the stakes of the 2024 election and what a second Trump term would mean, Wisconsin Democrats say their voters don’t need to be told the difference between winning and losing.

Democrats in Wisconsin spent eight years boxed out of power by Gov. Scott Walker and Republicans who held an iron grip on the state government, then four more with a gerrymandered Republican-led Legislature. Then they watched abortion become illegal overnight when a prohibition written in 1849 suddenly became law with the fall of Roe v. Wade. Party leaders in the state say there is a widespread understanding that the stakes are not theoretical.

“We organize year-round in Wisconsin,” said Lt. Gov. Sara Rodriguez. “We already have the infrastructure in place. We know how to do this, and we’ve been able to activate the folks who know what’s on the line.”

Mr. Biden has come to Wisconsin so many times — eight visits since he became president, and six for Vice President Kamala Harris — that for many Wisconsin Democrats, his visit on Wednesday comes almost as an afterthought.