The party that claims to have all the answers on Medicare seemed to have no interest in sharing them with the American people at its convention on Wednesday. The session, devoted to the theme of “We Can Change It,” never went any deeper than that slogan or a few others: Reform Medicare. Strengthen Medicare. Protect Medicare.

All without the slightest hint of how that supposed reform or strengthening would take place, regarding that program and many others. “We will not duck the tough issues; we will lead,” said Representative Paul Ryan, in his speech accepting the vice-presidential nomination. “We will not spend four years blaming others; we will take responsibility.”

Sounds great, except that the speech ducked the tough issues and blamed others for the problems.

Mr. Ryan, who rose to prominence on the Republican barricades with a plan to turn Medicare into a voucher system, never uttered the word “voucher” to the convention. He said Medicare was there for his grandmother and mother, but neglected to say that he considers it too generous to be there in the same form for future grandmothers (while firmly opposing the higher taxes on the rich that could keep it strong). He never mentioned his plan to abandon Medicaid on the doorstep of the states, or that his budget wouldn’t come close to a balance for 28 years.

The reasons for that are clear: Details are a turn-off, at a boisterous convention or apparently in a full campaign. A New York Times poll last week showed that the Medicare plan advocated by Mr. Ryan and Mitt Romney was highly unpopular in the swing states of Florida, Ohio and Wisconsin. As soon as voters find out that the Republicans plan to offer retirees a fixed amount, they disapprove, clearly preferring the existing system.