“Black Panther Party using violence as a lever” is a conservative talking point before there was Fox News.
Self-Defense was in the name and there were plenty of reasons for Black men in the 1960s to need self-defense from racist white people. White mobs were killing Black people for voting and registering Black people to vote. Self-defense was crucial to building a political movement that could withstand the violence that had derailed progress over the last 100 years post-Civil War.
Here’s a good interview that explains it.
https://theundefeated.com/features/the-truth-about-the-party-that-brought-power-to-the-people/
Joiner: In some circles, the Black Panthers were considered militant and opposed to the nonviolent actions of Dr. King.
Seale: Not true. We exercised the First Amendment of the Constitution of the United States of America that, by law, gives us the right, the civil right, to peacefully assemble and to peacefully redress our grievances. We had numerous peaceful rallies, etc. all across this country, just like Dr. King. The only thing we said was, ‘If these racists come in here and attack us, we will defend ourselves.’ That’s all we said. We will defend ourselves. If you come in here shooting at us, we will defend ourselves. We’re defending our constitutional, democratic civil human rights to have peaceful protest, to be able to register to vote, to be able to unify our people, to be able to win some of those political power seats and further move to change the laws and the racist city charters and supervisorial city charters and our county seats and stuff.