A second Republican candidate will challenge Sen. Deb Fischer in next May's GOP primary election.
Retired University of Nebraska at Omaha mathematics professor Jack Heidel announced Monday he will enter the Senate race with a focus on reducing the national debt.
Heidel will formally announce his candidacy at a news conference Wednesday on the UNO campus.
A few weeks ago, he said, Fischer joined other Senate Republicans in voting for a tax reform bill that will increase the national debt by $1 trillion over the next decade.
"The best features of the new tax law could have been enacted without increasing the debt," Heidel said.
That vote, he said, was "highly irresponsible."
"When (senators) ignore their most basic responsibilities to the people, they need to be challenged in the political process," he said. "This is what I am doing."
Heidel was a Republican candidate for metropolitan Omaha's House seat in 2012.
Todd Watson of Lincoln is also a candidate in next May's Republican Senate primary election.