Money from billionaire continues to pour in for GOP Senate candidate Kevin Nicholson

The billionaire founder of shipping and packaging supply giant Uline Corp. continues to spend big on Wisconsin's U.S. Senate race in support of Delafield businessman Kevin Nicholson.

Richard Uihlein gave $500,000 last month to the newly formed Club for Growth Action Wisconsin super PAC, which supports Nicholson. Uihlein has given nearly $16 million since 2017 to eight groups that are supporting Nicholson in his Aug. 14 Republican primary against state Sen. Leah Vukmir.

The winner of that primary will face incumbent Sen. Tammy Baldwin, the Republican Party’s top target, in November.

Spending by the groups Uilhein supports has helped make the Senate race the most expensive in the country so far.

The Center for Responsive Politics says so far $4.8 million has been spent by outside groups in support of Nicholson, while $3.1 million has been spent against Democratic Baldwin.

Outside groups have spent $909,000 so far for Vukmir.

Democratic Party spokesman Brad Bainum says Nicholson is “bought and paid for” by Uihlein.

Aside from Uilhein’s third-party spending, Nicholson says his campaign raised more than $1 million in the first three months of the year. That’s up from the $800,000 he raised in the last three months of 2017.

Vukmir has not reported how much she raised over the period.

Nicholson's campaign has raised more than $2.3 million since launching last July. He reports having more than $800,000 cash on hand. 

Baldwin has raised more than $3.7 million over the first three months of the year, more than triple Nicholson. She raised nearly $1 million more between January and March than the $2.8 million she collected in the last three months of 2017.