WATERTOWN, Wis. — Wisconsin’s US Senate race could help decide the control of the upper house this November as longtime Democratic politician and incumbent Tammy Baldwin attempts to ward off wealthy Republican businessman Eric Hovde’s challenge.

While Democrats call Hovde a “walking conflict of interest” for not revealing his bank’s foreign-government investors, Baldwin’s financial disclosures — or lack thereof — bear closer inspection.

Baldwin co-owns a $1.3 million DC penthouse condo with her partner, Wall Street private wealth management adviser Maria Brisbane but hasn’t included any of their jointly owned assets on her financial-disclosure reports — despite reporting the assets of her previous partner. In fact, Brisbane has never appeared on the senator’s reports.

The 2015 Tammy Baldwin might have objected to this arrangement.

In a press conference that year introducing her Financial Services Conflict of Interest Act with the late Rep. Elijah Cummings (D-Md.), the two-term senator declared: “The American people can’t afford to have government officials in the pocket of the financial industry that they are charged with overseeing.”

Baldwin’s bill, meant to close the “revolving door” between Wall Street and Washington, targeted potential conflicts of interest between the financial sector and those who regulate the industry, including expanding a cooling-off period prohibiting former government employees from lobbying for two years.

The bill was aimed at the executive branch and did not touch on congressional conflicts of interest with Wall Street.

“Hard-working middle-class families can’t afford to have the financial industry and government creating cozy relationships that allow Wall Street to write its own rules,” said Baldwin in 2015. That was three years before she reportedly began dating a Wall Streeter herself and six years before she and Brisbane bought their DC condo.

Brisbane is the founder of Brisbane Group, whose archived website from when it was at Merrill Lynch (archived at the end of 2023) claimed to “enhance performance” by investing in “small biotechnology” companies.

Brisbane previously managed a “biotechnology mutual fund” at Merrill Lynch, where she was said to have an appreciation for cutting-edge research that informs her current investments in biotech companies. Brisbane is also on the Cancer Research and Treatment Fund board of directors, who “rapidly deploy funding to the frontlines of research.”

“Sen. Baldwin, and all members of Congress for that matter, should adhere to the standards of transparency that were designed to avoid actual and perceived conflicts of interest or personal benefit,” Americans for Public Trust executive director Caitlin Sutherland told The Post.

“This situation raises serious ethical questions and will require additional scrutiny to ensure Sen. Baldwin is not taking advantage of her public office for her and her partner’s financial gain.”

The Wisconsin senator, who proudly voted with President Biden 96% of the time, claimed to “deliver” more than $49 million to “grow the biohealth economy and create jobs” in a July press release. The publicly funded “Tech Hub” is projected — though without evidence — to create $9 billion in economic development for Wisconsin in 10 years.

Baldwin said she “met privately” with US Secretary of Commerce Gina Raimondo to “make a final pitch” for Wisconsin to win the Phase 2 Implementation Grant as a Biohealth Tech Hub.

The Wisconsin senator’s role in securing funding for biotech companies is no secret.

Baldwin also chairs the Senate Appropriations Subcommittee on Labor, Health and Human Services, Education, and Related Agencies, which manages appropriations for the National Institutes for Health.

In 2018, a biotech CEO thanked Baldwin for her “support” after her firm received an award from one of the relevant NIH programs. That CEO, Ayla Annac, contributed nearly $4,000 to Baldwin, including more than $1,000 in the months before and after she thanked Baldwin. Baldwin also included Annac in the Business Leaders for Tammy coalition one month before the CEO thanked the senator for her help.

NIH is the largest public funder of biotech startups, whose long on-ramp for research and development, clinical trials and regulatory approval requirements create a high-risk, high-reward situation for investors.

The NIH manages a budget of $1.3 billion dedicated to programs that provide funding to for-profit small businesses — including biotech companies — focusing on technologies like research tools, diagnostics, digital health, drugs and medical devices.

Between 2018 — the year Baldwin began dating Brisbane — and 2020, Health and Human Services and NIH doled out 71 awards to the tune of $45 million to small businesses that are owned in part by venture-capital firms, hedge funds, and/or private-equity firms.

The NIH website states that “many companies leverage NIH funding to attract the partners and investors needed to take an innovation to market.”

Baldwin and members of Congress in general are not in a position to choose grant applicants for this funding — that job belongs to the NIH.

But well-documented problems with insider trading among members of Congress call for higher levels of scrutiny.

Brisbane’s firm helps “Ultra High Net Worth” clients with estate planning and provides access to
investment opportunities in private-equity funds, venture-capital funds and hedge funds.

The minimum account requirement to work with Brisbane was $20 million and her typical client’s net worth was between $40 million and $200 million, per Forbes.

“Wisconsin voters deserve to know whether Sen. Baldwin is using inside information to help her partner and her ‘ultra rich’ clients cash in big,” Hovde campaign spokesman Ben Voelkel told The Post.

“There are massive conflicts of interest here that merit further examination — just the kind we’ve sadly come to expect from career Washington politicians like Sen. Baldwin who put special interests first.”

While Democrats accuse Hovde of evading taxes, Brisbane’s firm advertises “tax minimization” services to her ultra-high-net-worth clients.

Baldwin, who opens her speeches accusing Hovde of spending time at his California properties, has already run into ethics issues involving Brisbane and abuse of taxpayer money. In September 2023, Fox News reported that Baldwin used taxpayer dollars to fund a personal trip to visit her partner in New York.

In a potentially comparable situation, in 2023, the American Accountability Foundation filed a complaint with the Senate Select Committee on Ethics and called for an investigation into Sen. Kyrsten Sinema’s (I-Ariz.) alleged failure to disclose the assets and income of a woman Sinema treated as a spouse for official travel in the past and with whom she lived.

A disclosure ensuring that Baldwin’s position as chair of a subcommittee that manages the NIH’s appropriations and her larger efforts to secure biotech startup funding do not benefit her partner’s firm or clients would alleviate conflict-of-interest concerns.

As the senator’s co-author, the late Rep. Cummings, said at their 2015 press conference, “One thing [the American people] do want to know is that their government is transparent and that it is fair.”

“Tammy Baldwin has always been proud to support research into cancer and Alzheimer’s and will not back down in the face of desperate and false attacks,” Andrew Mamo, Baldwin’s campaign spokesman, told The Post when contacted for comment.

Democrats are outspending Republicans 2-1 in the race, which Cook Political Report rates leans Democrat.