Wisconsin Lieutenant Governor Mandela Barnes formally secured a key Democratic nomination in his bid for the US Senate Tuesday. The win for Barnes came after three top Democratic rivals, who had spent roughly $25 million on their campaigns, acknowledged in late July that Barnes was ahead, folded their campaigns, and endorsed the lieutenant governor.

In an eight-candidate field, where several rivals were still actively campaigning, Barnes won more than 77 percent of the vote. The three Democrats, who had endorsed Barnes after they had earned substantial totals in early voting, took another 19 percent.

Barnes swept every one of Wisconsin’s 72 counties. In a number of counties, he took more than 80 percent of the vote—winning especially wide margins in Dane and Milwaukee counties, as well as in the rural counties where Barnes, an ardent advocate for family farmers, focused much of his attention as an elected official and candidate.

But there was more to the victory than the headlines that announced “Barnes wins Democratic Senate primary in Wisconsin, finalizing showdown with Ron Johnson” and “Wisconsin Dems rally behind potential history-maker Mandela Barnes in lead-up to key race.”

A progressive backed by Vermont Senator Bernie Sanders and Massachusetts Senator Elizabeth Warren, as well as the Working Families Party and Progressive Change Campaign Committee, Barnes is part of a new wave of millennial candidates. And if he defeats Republican incumbent Ron Johnson in November, he would become the first Black senator from Wisconsin. A Barnes win—along with a win by Democrat John Fetterman in Pennsylvania—would give Democrats a wide enough majority to govern with a boldness that has been impossible in an evenly split Senate, where Democrats Joe Manchin of West Virginia and Kyrsten Sinema of Arizona have refused to overturn the filibuster.

“A 50-50 Senate is just not enough.” says Barnes, who bluntly declares, “Let’s be clear: the filibuster has been weaponized by the GOP—and they’re destroying our democracy.”

With stakes so high, the Wisconsin race will be a blockbuster, with tens of millions spent and charges and countercharges flying from not just the candidates and parties but also outside groups. The limited polling available puts Barnes slightly ahead. The Democrat leads Johnson 46-44, according to a pre-primary survey conducted by Marquette University Law School’s well-regarded polling operation. In that survey, Barnes trailed among Republicans but narrowly led with independents. Predictably, the lieutenant governor was far ahead among Democrats in the one-on-one matchup with Johnson: 91 percent to 5 percent.

What was notable in that survey was that Johnson did not show quite as much strength among Republicans as Barnes did among Democrats. The incumbent got support of just 86 percent among GOP voters. Those numbers suggested that there was something of a Republican enthusiasm gap for Johnson. That could be consequential in a state where four of the past six presidential races have been decided by under 25,000 votes, and where the most recent races for governor and attorney general were determined by under 30,000 votes.

Has Johnson turned off a significant number of the folks who are supposed to form his base, with his scandals and conspiracy theories about the coronavirus pandemic and vaccinations, as well as elections and a host of other issues? Is it possible that Johnson could suffer a fall-off in support among more moderate and responsible Republicans—as did the senator’s close ally, Donald Trump, in 2020, when Wisconsin flipped to Democrat Joe Biden?

The numbers from Tuesday’s primary were even worse for Johnson than those from the Marquette Poll.

Johnson faced a little-known Republican primary challenger named David Schroeder. A semi-retired former educator and postal worker, Schroeder entered the race with a declaration that “I have become increasingly embarrassed and disgusted with how I have been misrepresented in Washington by the incumbent. I am running to replace him because he does not represent the economic, political, or societal interests of the majority of his constituents.”

Sharply critical of Johnson, Schroeder noted that the incumbent “was banned from Facebook for spreading harmful misinformation” about treatments for Covid-19 and “in violation of his oath of office…volunteered to deliver a list of fraudulent electors to the Vice President, personally participating in an attempt to overturn a free and fair election, by nullifying not just the votes of his perceived political opponents but all of our votes in the State.”

Johnson’s spent more than $15 million, blanketing the airwaves with ads. Schroeder spent almost nothing and rarely appeared on TV. There were no debates or town hall forums featuring the two Republicans. Yet, on Tuesday, Schroeder won nearly 110,000 votes and took 16.3 percent of the GOP total. In more than a dozen counties, Schroeder won over 20 percent of the vote. In several counties, he won over 25 percent.

So it looks like Johnson is vulnerable among Republicans. How vulnerable remains to be seen. But in a state that, historically, has been closely divided, that’s a problem for the incumbent, especially in the rural western Wisconsin counties where Barnes won some of his best totals. Consider Iowa County, where Barnes won 82 percent against multiple active and inactive opponents on Democratic side, while Johnson gained just 73 percent of the vote against a single opponent on the Republican side. In neighboring Richland County, Barnes won 81 percent of the Democratic vote, while Johnson secured only 75 percent of the GOP vote.

Perhaps the lieutenant governor should start a “Republicans for Barnes” campaign.