Tonight’s hourlong “NOW” special, “Global Health: America’s Response” (8 p.m., PBS), takes a provocative look at America’s efforts to eradicate AIDS in Africa.

While it hasn’t received coverage equal to that of the invasion of Iraq or Supreme Court nominations, the administration’s stand on AIDS may be the most important part of the Bush legacy.

Spending on AIDS treatment and prevention in Africa expanded exponentially under this administration, from less than $400 million to $15 billion. And as this thoughtful documentary explains, this new emphasis and explosion in funding has a lot to do with changing attitudes toward AIDS by conservative Christians, a major Republican constituency.

But while Bush has convinced conservative politicians to spend billions on AIDS, Congress has insisted that at least 30 percent of those funds be earmarked for teaching abstinence. “NOW” looks at successful programs in Uganda that have cut that nation’s cataclysmic rate of AIDS infection and talks to activists on both sides of the issues of condoms and abstinence.

“NOW” will precede this special with a half-hour interview with former President Carter (7:30 p.m., PBS). He discusses a recent trip to Ethiopia and efforts to eradicate Trachoma, a painful cause of blindness.

Tonight’s other highlights

¢ An unsettled spirit can’t understand how she died during “routine” surgery on “Ghost Whisperer” (7 p.m., CBS).

¢ Scheduled on “Dateline” (7 p.m., NBC): Adults use the Internet to find underage prey.

¢ Wanda embraces corporal punishment with too much gusto on “Bernie Mac” (7 p.m., Fox).

¢ Manipulating mom on “Malcolm in the Middle” (7:30 p.m., Fox).

¢ A preacher’s visions seem frightening and familiar on “Threshold” (8 p.m., CBS).

¢ An anti-terror drill goes haywire on “Numb3rs” (9 p.m., CBS).

¢ Scheduled on “20/20” (9 p.m., ABC): deadbeat dads; Nicole Richie; lingerie.