Mr. Daniels said his party’s candidates had a responsibility to conduct a “more candid and honest” conversation about the nation’s financial burdens, particularly Social Security and Medicare.

“Somebody else could still enter and have a competitive chance,” Mr. Daniels said in a weekend interview. “The candidate I could get instantly excited about is someone who is willing to level with the American people and assume they are prepared to listen to the mathematical facts and agree that whatever other disagreements we have aren’t as important.”…

“I don’t think any of this is very helpful,” Mr. Daniels said. “If there’s a problem with ‘Ponzi scheme,’ it is that it’s too frank, not that it’s wrong. But by stopping there, he might be unnecessarily scaring people.”