"Zuckerbucks" is officially no more in Wisconsin after voters approved a ban on private funding in elections Tuesday.

The move is a potential blow to Joe Biden, who narrowly flipped Wisconsin in the 2020 election amidst a massive shift to mail-in voting.

One of the ingredients to Biden's success was an infusion of $350 million from Facebook founder Mark Zuckerberg that passed through the liberal nonprofit Center for Tech and Civic Life.

The money was meant to help administer the election during the COVID pandemic, but most of it went toward boosting turnout in heavily Democratic cities.

"Zuckerbucks" banned in WI

In Wisconsin, Zuckerberg sent $10 million to largely Democratic cities like Milwaukee and Madison.

Democrats - despite making opposition to "dark money" a staple in their rhetoric - opposed the effort to ban Zuckerbucks in Wisconsin, arguing it would make elections harder to administer.

54 percent of Wisconsin voters approved the constitutional amendment banning "Zuckerbucks."  A related amendment clarifying that only election officials can administer elections also passed.

Republicans said voters had sent a clear message about wanting fairness and transparency in elections.

“Wisconsin has spoken and the message is clear: elections belong to voters, not out-of-state billionaires,” said state GOP Chairman Brian Schimming in a statement.

The vote is part of an ongoing battle over election integrity that exploded in 2020, when the country made a massive shift to voting by mail.

Democrats have opposed efforts to return to a more ordinary status quo, while Republicans have emphasized a need to restore trust in the process.

Battle over election rules in WI

Wisconsin, a pivotal swing state in the country's Midwestern battleground, is at the center of battles over election administration and the role played in those fights by state courts.

The state's Democratic governor, Tony Evers, has asked the state Supreme Court to rescind a ban on ballot drop boxes that was handed down by the court before it flipped to liberal control.

Evers previously vetoed an effort by the state's Republicans to ban Zuckerbucks through the legislature.

Wisconsin was won by President Trump in 2016 before Biden brought it back under Democratic control by just 20,000 votes in 2020.

TIME famously boasted after the fact about an elaborate conspiracy to "fortify" the election that included a shout out to Zuckerberg.