According to a study published in September in the scientific journal The Lancet H.I.V., nearly all of the 215 H.I.V. infections that resulted from the outbreak could have been prevented — if the state’s elected officials had more quickly heeded the advice of public health experts.

Mr. Pence’s slow, own-foot-shooting response to the H.I.V. crisis in his home state bears many lessons for his current boss, President Trump, who recently announced a plan to eradicate H.I.V. in the United States by 2030.

Mr. Trump’s plan has some promising features. Developed by career civil servants with decades of experience combating H.I.V., it would provide the first new funding for the domestic fight against this disease in many years . And it would deploy a majority of those dollars to communities where the virus is most prevalent and resources most urgently needed.

But as The Times reported this week, the president’s proposed budget for the initiative — $291 million for the first year — falls far short of what’s needed to reach the stated goal. And like Mr. Pence’s efforts in Indiana, many of the Trump administration’s other policies stand to undermine this initiative.

Roughly one million Americans live with H.I.V. today; one million more are at risk of contracting it. A vast majority of those who are infected live in marginalized communities, and 15 percent of them have not been diagnosed. Conquering the disease will require making health care as widely accessible as possible. But the same budget proposal that would offer new money for fighting H.I.V. seeks to cut funds for Medicaid, a program that health officials say is a bedrock for people living with the virus. (It’s no surprise that the region of the country with the highest H.I.V. burden — the South — also has the lowest participation in Medicaid expansion under the Affordable Care Act.)