Waukesha — U.S. Sen. Ron Johnson received the endorsement of the U.S. Chamber of Commerce on Wednesday, a boost for his campaign and a reflection of the national political stakes at play in Wisconsin.

The Republican from Oshkosh is in a hard-fought race against Democrat Russ Feingold, the man he defeated in 2010. Republicans hold an eight-seat edge in the Senate but are defending 24 seats this fall, against 10 for the Democrats.

Johnson was the first Senate candidate to receive the Chamber’s public endorsement in this election cycle, a sign that the powerful business lobby was prepared to put a significant amount of money into the race.

The endorsement also signaled that even though Johnson has trailed Feingold by double digits in recent Marquette University Law School polls, the race still was viewed as winnable for the Republican incumbent.

The news was rolled out during stops in Wausau, Green Bay and Waukesha.

“We’re bullish on this race and Senator Johnson’s campaign because he has a record focused on governing and getting things done,” said Rob Engstrom, national political director of the U.S. Chamber of Commerce.

After speaking with two dozen blue-collar workers at Weldall Manufacturing, Johnson said, “You just look at who the Chamber represents, it really is mom-and-pop shops, retailers, really the backbone of this economy….This means a lot to me. I was highly active in the Chamber.”

Engstrom said there is a clear choice between Johnson and Feingold on key issues and that voters would support Johnson because of “that fundamental difference.”

“Senator Johnson is plain-spoken and you know where he stands on the issues,” Engstrom said, adding that Johnson “comes from the free-enterprise system. He understands how hard it is to grow jobs in this economy.”

Asked how the organization would deploy resources in the race, Engstrom said: “I don’t ever give away my grandmother’s chicken soup recipe before I serve it. If you look back to 2012, if you look back to 2014, when there is a fundamental difference between candidates on our issues, we have a vigorous, aggressive and vocal approach to ensuring the voters know where the candidates stand on the issues. I believe that will be the case in Wisconsin, also.”