U.S. Sen. Chuck Grassley recently said Congressman Steve King is facing the toughest race of his career.

Census redistricting took King, R-Kiron, out of U.S. District 5, a seat the Conservative Catholic has held for the last decade, and put him up against Democrat Christie Vilsack, of Ames, Iowa's former first lady and wife of U.S. Secretary of Agriculture Tom Vilsack for the new District 4.

If Vilsack won, she would be the first Iowa woman elected to US Congress. But Grassley doesn't seem to think that she will be making history come November.

He recently told the Des Moines Register that he believes King is in the toughest race of his career, but said “I don't think it is possible to see an upset.”

According to the Daily Times Herald, a paper in Carroll, registered voters in the district are a mix of Independents, Republicans and Democrats. There are 182,592 registered independents in the 39 counties, 177,130 Republicans and 134,819 registered Democrats, the article stated.

King said during a visit to the Ames Pizza Ranch earlier this month that he also felt the race would be tough, saying the race against Vilsack would become the most expensive Congressional race in Iowa history. Three Political Action Committees have aligned against him already, he said.

One of them, the CREDO Super PAC (leading the Take Down the Tea Party 10), has opened an office in Ames and has planned a grand opening 6 p.m. April 28. Alec Johnson, the PACs district director, invited about 30 people rallying against tax loopholes for the wealthy and King to the event after their protest Tuesday outside the former Workforce Development office in Ames.

The flier Johnson passed out said, “Please join us as we celebrate the Grand Opening of our Take Down King Campaign Headquarters.”