Campaign finance reports show Republican Senate candidate Mark Jacobs has put $1.6 million of his own money into the race, bringing his investment to more than $3 million.
The reports filed this week show the former energy executive contributed the money between April 1 and May 16.
Jacobs is seeking the GOP nomination to run against Democrat Bruce Braley in the fall general election. The Quad-City Times reports his cash infusion gave him a nearly 3-1 lead in cash on hand going into the last few weeks before the June 3 primary.
Jacobs is in a five-way race that includes state Sen. Joni Ernst. She raised more than $410,000 in the same period. Jacobs reported having $1.2 million in the bank as of May 14; Ernst had nearly $352,000.