Republican state Sen. Jim Oberweis has given his campaign for U.S. Senate $500,000 of his own money as he tries to win a statewide primary election for the first time.
The federal campaign finance report due Friday shows the Sugar Grove dairy businessman also raised about $105,000 from other people in his race against Republican Doug Truax of Downers Grove.
"When he commits, he's all in," said Oberweis campaign director Tom Mannix.
Oberweis finished second in the 2002 and 2004 Republican primaries for Senate, and also finished second in the 2006 GOP primary for governor.
Truax is a first-time candidate who is pointing to his military background and business experience helping companies make health care decisions to try to overcome Oberweis' more recognizable name and likely financial advantage.
He points to endorsements from suburban GOP groups to argue his campaign has come a long way in a short time.
"Nobody had heard of me before July," Truax said.
The March 18 winner would be set to face Democratic U.S. Sen. Dick Durbin of Springfield in November.
Oberweis has spent millions of dollars of his own money in previous campaigns.
In 2012, he won election to the Illinois Senate.
Before that, he was defeated by Democrat Bill foster in 2008 elections to succeed former U.S. House Speaker Dennis Hastert in Congress.