My understanding is that the FBI spent significant time and resources dismantling the Black Panther Party, up to and including assassinating Fred Hampton. I know there were some incidents where Panthers fought with police, and that their community organizing efforts may have created a significant base of support in certain places, but these incidents seem quite small scale compared to e.g. the CCP that they were influenced by.
Do historians believe that the party actually had - or was even close to having - the influence, membership, and material to actually pose a real threat of revolution in the US? Did Hoover and others within the FBI actually think such a threat was imminent, or did they see their efforts as preemptive?
Pre-emptive, but because they did pose a serious threat to the State if left unchecked.
Let's set the stage:
Communism was experiencing an uptick in radical spirit globally during the time the BPP existed, seen in the Cultural Revolution of China, a near miss of socialist revolution in France, and the revolutions in Vietnam, Mozambique, Angola, Cuba, so on. Communists worldwide were feeling the wind in their sails.
It was a pressing concern for the Government and the FBI policies can be seen as a natural extension of that thinking applied "to the home turf" - the US government never got worried about being unseated imminently, a la France 1968 where their president briefly fled the country during a general strike, but where would the world be in 10 years? Or 20? Or 30?
The bolsheviks only had about 10,000 members in 1906. by 1917 they were stringing up their Tsarist ministers on rope. As Lenin himself put it,
“There are decades where nothing happens; and there are weeks where decades happen
At the height of their influence, the BPP themselves only had 5,000 members. But here is the kicker: A poll in 1970 showed that 25% of Black people in Amerca believed the BPP represented their views (PDF link) - also keep in mind that MLK, America's ultimate symbol of nonviolent resistance, had been assassinated just 2 years ago.
No matter could be taken lightly, by all involved, between the titanic struggle of two competing and incompatible futures for the global economy. And it may be titanic when you zoom out but in all of this you ultimately find millions of people across the world, honest people in all sides, diligently throwing their life into one future or the other, making daily decisions to see through one or the other victory. No matter was too small, no person unimportant, whatever you ignore today may bear a nasty surprise in only a few years time.
Back to an earlier point, connecting it to this - do you know where the world will be in 20 years? No. Now put yourself in the middle of the 60's and good luck staying even remotely sane.
What is The Party:
Their numbers, like the Bolsheviks in 1906, were nominally small, but the goal was not be open to any and all, the goal was to be correct, and then win popularity by being effective. This was achieved via disciplined cadre - professional full time revolutonaries - who could effectively coordinate mass unrest and focus diffuse anger into precise lasers. The goal is revolution during a total economic meltdown, but they would be quite busy every day and in every smaller form of crisis as well.
Like when someone says, oh, there are 40 million or so Democrats in 2022, that just means you cast a vote. Being a member in a group like BPP was something you had to apply for and which carried strict rules.
There would be places with only 15 panthers but those 15 panthers have 5 guys with rifles who will supervise the police arrests while shouting out legal advice, 5 people running daily meetings on revolutionary education, and 5 people running a soup kitchen, meaning the actual influence and base of support was much, much larger.
A bullet point program drawn up by 2 people at a dining room table, adhered to by 5,000 people, explicitly calling the government illegitimate and winning the confidence of millions.
The FBI was extremely concerned.
FBI Director J. Edgar Hoover believed strongly that “the Black Panther Party, without question, represents the greatest threat to internal security of the country”
https://onlineexhibits.library.yale.edu/s/black-panther-may-day/page/the-black-panthers-and-the-fb
Why is The Party:
http://historymatters.gmu.edu/d/6445/
The rationale can be put more clearly, linked above is their 10 point program, which all Panthers were expected to uphold and dedicate themselves to, above the value of their own life (Serve the People, not yourself.)
The Black Panther Party did not view Black people as Americans, rather, the BPP connected the US government with White Capital Rule, and presented it as a menace to all people of the world. They connected black identity to anticolonial revolution that was still on the upswing globally and their program even reiterates the opening lines of The Declaration of Independence. You'll also find slogans in their material such as
Get the Imperialist out of Latin America, get him out of Asia, get him out Africa, and get him out of the Ghetto!
Police were not public servants in Black communities, rather, they are the armed wing of a White colonial occupation, any and all means were therefore on the table to fight the government. Shooting a cop becomes a mere tactical question - there is no valid social contract and they are not your public servants, so who gives a shit, "it's war, the police have no sympathy for us and we have no sympathy for them" - Does this or that fight grow party power? Does it Serve the People and the Global Proletariat? Will it repel state power or aggravate the situation?
Here is a particularly poignant interview with Angela Davis, a prominent BPP member, where - when asked about the endorsement of political violence and revolution - she relates it immediately to white police terror, racist bombings killing Black civilians in her neighborhood, and the constant fear Blacks faced that motivated such a radical response. The FBI was complicit, such as enabling the Chicago Police assassination of Fred hampton, who got two gunshots to the back of his head in his sleep. The BPP were not just making shit up and thus had a real ability to make persuasive arguments to their communities, clarifying numerous real crimes practiced by de facto white rule, worker abuse, and police power. The Civil Rights Act abolished Jim Crow legally - but a law is just paper - and it was hardly realized as de facto liberty in the streets.
The ultimate goal was a referendum by and for Black people to form a new nation (Point 10 of their 10 Point Program) much aligned with Lenin's views on nationalism, so as to have a their own state resources for self determination. *Depending on which panther you asked, that meant working with whites as the Black faction of revolution (as seen in partnership with the White Panthers, Young Lords, and white student Maoists), or it meant separatism - leaving the White State behind to the dustbin of history by extracting a Black nation with guerilla war. The details were to be figured out as Black Power progressed.
Whatever the exact means, it involved unity between Blacks and other communists abroad, without much regard for existing national boundaries - which was particularly important for the BPP as Maoists tend to give a dim appraisal of the revolutionary potential of most workers in the US (via ideas like Labour Aristocracy). The BPP engaged in consistent collaboration with other communist parties abroad (which the US government basically held as treason).
*Edited to better represent the breadth of views within the BPP
How to manage them:
The FBI took them seriously, using whatever legal or illegal means of their own to deal with them, be it spurious charges, surveillance, and networks of informants and provocateur, and counter-propaganda. Black Panthers frequently occupied the FBI's 10 most wanted, usually in relation to their fights with police forces.
But this is a delicate balance, attack too harshly, and you make people more angry about the very repression that stirred em up in the first place. The other tool - granting concessions - is beyond the purview of the FBI. All of this focus has been on the stick but this was not the only tool at hand, for already being such a lengthy comment though, all I have to say is evidence reveals to also be a tricky balance - grant too little, it's a slap in the face, grant the wrong concessions, then revolutionaries can just use these against you directly or provide them as proof that their methods are the only way to secure progress.
But by the end of the 80's, it was safe to say FBI tactics had largely done their job. The Panthers were constantly beset by internal paranoia of spies that limited their ability to function, producing a long string of scandals that ruined public trust in their abilities. Major leaders were locked up, fled abroad, or shot dead, and the organization officially dissolved in 1982. But maybe moreso than a simple story of State Repression, communism was also globally losing thrust and esteem that would soon become a complete breakdown of Marxism Leninism across the world, leaving domestic radicalism unmoored and dissociated from notions of international class struggle, exploitable geopolitical cracks, and a tangible alternative modernity that groups like the BPP relied upon
Tangentially related reading:
1972, Committee of Internal Security Report on Maoists, presented to Congress. I have done my best to outline the context and motivations, motivations, tactics, and history going both into the practice of the BPP and FBI, but this document in particular will be of value to you.
You may also gain some insight from Bolshevik Revolutionary Viktor Serge's 1926 work, On Repression, where he gives a largely first hand account of the entire toolbag the Russian state police forces had for fighting revolutionary politics. The FBI were hardly as expansive or repressive as the Russian Okhrana, but many of the same basic practices apply to any form of counterinsurgency.