Don't act like then entire purpose of USAID and the entire definition of soft power is whatever 0.08% of one year's budget you've been told to hate today. Distributing HIV medication is soft power. Sending food aid is soft power (and good farm policy). Supporting democratic elections is soft power. If it's unarmed and promoting American interests and values it's soft power.
Don't talk down to me--I grew up around USAID and almost certainly know more about it than you. Nearly all our family friends are USAID or World Bank people. Virtually all of the people talking about USAID didn't know shit about it until it became another vector to play out their impotent rage at Trump.
Interfering in other countries' politics undermines American soft power and the mission of USAID. All the things you and I both like--vaccinations for kids, maternal health, etc.--require working with governments to executive effectively.
Interfering with domestic political affairs completely negates that. Governments will not trust a putative AID organization that is also bankrolling activist organizations in their countries. And approximately zero people in Asia/Africa/the Middle East have uniformly negative feelings about the U.S. meddling in their internal politics.