“He hit that very strong today. That’s a perfect message for Ohio,” Mr. DeWine added, after campaigning with him in Perrysburg.

But, as The Wall Street Journal’s conservative-friendly editorial page noted this month: “Mr. Santorum often gives the impression that he views the economy as a secondary issue, something he’ll get to after he saves the traditional family.”

Mr. Santorum’s speech on Tuesday night — not much of a concession speech — could be seen as a road map of how he might adjust his candidacy now. In Michigan, he veered off into controversial positions that may have alienated some voters, particularly women, and he devoted part of his speech to his mother and wife. He said that both are strong women who balanced professional careers and motherhood, perhaps an attempt to quell some of the anger that arose recently over passages in his 2005 book that took working mothers to task for not staying home.

He also addressed the economy.

Mr. Romney, who has made his business acumen the centerpiece of his campaign, senses that the economy, which voters say is their most important issue, is a major Santorum weakness. On Tuesday he called him “an economic lightweight.”

Mr. Santorum’s passion in his campaign speeches is reserved for what he calls economic freedom — from regulations and an intrusive government. That inevitably leads him to discuss President Obama and his health care law, a topic that gets Mr. Santorum’s blood boiling, and that of his listeners.

His biggest applause lines are often his attacks on the president and his portrayal of Mr. Obama is an elitist, someone who “knows better than you” how to spend your money — a portrayal that often fuels a sense of class warfare.