It was just six words from a 29-minute news conference, but President Barack Obama’s assertion that “the private sector is doing fine” looks primed to play a starring role in this already-fevered campaign season.

President Barack Obama discussed the euro-zone crisis and the overall state of the U.S. economy on Friday morning. Kathleen Madigan reports on Markets Hub. Photo: AFP/Getty Images.

In a discussion that focused in large part on Europe’s problems, Mr. Obama turned at one point to the U.S. He said Republicans needed to join him to help state and local governments that have continued to pare jobs while private-sector employment expands.

“The truth of the matter is that