Wisconsin’s U.S. Senate race, where incumbent Sen. Tammy Baldwin (D) is facing a strong challenge from Republicans Kevin Nicholson and state Sen. Leah Vukmir (R-Brookfield), is now ranked eighth by the national political news website Politico for most likely to switch parties. Wisconsin moved up two places from tenth in the Politico ranking.
8. Wisconsin — Democratic Sen. Tammy Baldwin running for reelection (10)
Trump won Wisconsin by a smaller margin than he won some other states on this list, but Wisconsin is rising because of the money already directed at Baldwin, arguably the only unabashed progressive among the Democrats in our top 10. The Koch brothers network of conservative donors and GOP super-donor Richard Uihlein have both targeted the race, pouring millions into attacks ads targeting Baldwin. Baldwin, like other Democratic incumbents, has two advantages: a substantial lead in hard money ($6.9 million in the bank), and a nasty primary between businessman and veteran Kevin Nicholson and state Sen. Leah Vukmir.
In addition to Vukmir and Nicholson, businessman Eric Hovde is also considering entering the GOP primary. Hovde finished second behind former Governor Tommy Thompson in 2012 in the GOP Senate primary election, and Thompson then went on to lose to Baldwin when he did not have the resources to counter her attacks after the divisive GOP primary.