Wisconsin Lt. Gov. Mandela Barnes, Democratic candidate for US Senate, speaks to the press during a campaign rally on September 24, 2022 in Milwaukee.
CNN  — 

Democratic Senate candidate Mandela Barnes raised more than $20 million in the third quarter of 2022, according to details from the Wisconsin lieutenant governor’s campaign, dwarfing what he raised throughout his entire bid for Senate.

Barnes is aiming to unseat Sen. Ron Johnson, the Republican incumbent who is seeking a third term, in what has become one of the most closely watched Senate campaigns of the midterms. With an evenly divided Senate, every race this November could tilt the balance of power in the legislative body, but Barnes’ race against Johnson represents one of the best chances for Democrats to flip a Senate seat this cycle.

The race has been tight for months. A Marquette University Law School Poll, released in mid-September, found 49% of likely voters in Wisconsin supported Johnson, compared to 48% who backed Barnes – a statistical dead heat. But the poll was an improvement for Johnson: The same poll had found Barnes at 52% in August with the incumbent at 45%.

Barnes’ fundraising haul should help Democrats level the advertising playing field in the race after being outspent in September.

According to AdImpact, Republicans spent nearly $22.5 million on ads in September, compared to $16.5 million for Democrats. The biggest spenders in the race over that time was Senate Leadership Fund, the Republican super PAC with close ties to Senate Minority Leader Mitch McConnell. The group spent nearly $8 million in September. Senate Majority PAC, the predominant Democratic super PAC focused on Senate races, spent just over $6 million.

While Republicans spend money hammering him on crime, Barnes has attempted to focus his campaign on the major issue motivating Democratic voters in 2022 in the wake of June’s Supreme Court decision overturning Roe v. Wade: Abortion.

“I’m proud of the grassroots coalition we’ve built across Wisconsin,” Barnes said in a statement to CNN. “Over this final stretch we’ll keep going everywhere and holding Ron Johnson accountable for his record of supporting a dangerous abortion ban with no exceptions for rape, incest, or the life of the woman. He’s out of touch with Wisconsin values and we’re going to send him packing.”

The Democrat recently launched a statewide tour the campaign has dubbed “Ron Against Roe,” an effort it hopes will take advantage of opposition to the June Supreme Court ruling. Marquette’s polling found more than 60% of Wisconsin voters opposed that decision. Barnes also rolled out a new ad that attacks Johnson for supporting a 2011 bill that was introduced by Mississippi Sen. Roger Wicker that would have enshrined “the right to life” upon conception.

“It’s Johnson’s views that are alarming. Johnson supported a ban on abortion, he cosponsored a bill that makes no exceptions for rape or incest or the life of the woman. And Johnson said if women don’t like it, they can move,” a narrator says in a new Barnes ad.

Johnson has since tried to push back against the abortion attacks by saying he believes the issue should be left to Wisconsin voters, including by updating an 1849 law that bans nearly all abortions to include exceptions for rape, incest or if the life of the mother is at stake. But Johnson backed the Supreme Court’s overturning of Roe v. Wade and has numerous times put his name on a bill that would make it illegal to perform an abortion 20 weeks after conception.

While Barnes focuses on abortion, Johnson’s campaign has been laser focused on attacking the Democrat over crime, including touting endorsements from law enforcement organizations and running ads tying Barnes to efforts to “defund the police.”

“Mandela Barnes: Dangerously liberal on crime,” a narrator says in a recent ad before showing Johnson standing next to a police officer.

Ben Voelkel, a spokesman for Johnson, responded to Barnes’ fundraising haul by saying, “All the out of state liberal money in the world can’t change the fact Mandela Barnes supports the Defund the Police and Abolish ICE movements, wants to cut the prison population in half and backs the same Biden economic policies that have led to 40-year high inflation and record gas prices.”

Barnes has responded by refuting the defund accusations, including with an ad that shows a retired sergeant for the Racine Police Department testifying that Barnes “does not want to defund the police.”