Medically, the afflictions are quite different, and AIDS in the early days appears to have been much deadlier than Covid-19 today. Socially, the stigma that affected early cases of H.I.V. and AIDS is largely absent today.

The latest news and analysis on the spread of and response to coronavirus.

Joe Biden’s victory in the Michigan primary is raising hopes he can rebuild the “blue wall,” but Robert David Sullivan writes that a Democratic coalition may not be easy to assemble this fall.

About one-fourth of U.S. Latino voters strongly support President Trump. The positive direction of the economy is a major reason for their approval, writes J.D. Long-García.

Super Tuesday voters were not keen on a contested convention, writes Robert David Sullivan, and Sanders fumbled his opportunity to unite the Democratic Party.

The stop-Sanders movement is coalescing around Joe Biden, writes Robert David Sullivan, but is it too late? Super Tuesday may provide the answer.