Republicans are paying close attention to the shocking defeat of House Majority Leader Eric Cantor.
Cantor was upset in his Republican primary in Virginia Tuesday by Tea Party candidate Dave Brat. Just hours after the defeat, Cantor told fellow Republicans on Wednesday that he's stepping down as the House Majority Leader.
Cantor was heavily favored in his early polling - some of the same pollsters South Dakota Republicans have used in the past.
Some are calling Cantor's loss a political earthquake. South Dakota Republicans say they are paying attention to the aftershocks.
"If you wanted a textbook example of why it's important to turn out your vote that would be one. I mean the Republican leader and he's bounced out with a miniscule turnout of votes. He just got caught," South Dakota GOP Chairman Craig Lawrence said.
Lawrence says Cantor's loss is proof that you can't relax in any election, including the November general election in South Dakota where Republicans are currently favored.
"As Republicans, we're not going to take anything for granted. We may have a 50,000 registered vote margin over Democrats, but we're not taking anything for granted," Lawrence said.
"The takeaway in all this obviously is that you've got to work very, very hard; never leave anything to chance. Never take anything for granted," South Dakota Senator John Thune said.
South Dakota Republican Congresswoman Kristi Noem works closely with Cantor in the House.
"The result of the Majority Leader's election last night came as a complete surprise to me and to all the colleagues I've talked with, both Republican and Democrat,” Noem said in a statement. “I appreciate that Eric always listens to my perspective and concerns on behalf of South Dakotans."
At the same time, South Dakota Republicans say they will learn a lesson from an upset that caught nearly everyone by surprise.
Cantor will resign as the House Majority Leader at the end of July.