The new left is indeed broad. From the dead-end strands of ultra-left to the dead-end strands of right-opportunist to even the outright off the deep end "post-left" banditry and ultra-left to reactionary pipeline that existed among the ultras intelligentsia.

It had its bed of kindling rooted in the beginning of the cold war and how the "iron curtain" built by the western powers slowly began to isolate the Communist parties in the West from the Communist parties in the East. The first spark to ignite the great sundering of the international Communist movement was the death of Stalin and slanderous lies of Khrushchev.

The fuel that grew the conflagration was the movements of the state apparatus' in the West against the Communist Parties. These were the Red Scares and Gladios would scare off, drive underground, frame for crimes, or outright murder the veteran Communists in the West and wreck much of the work they had built up through the generations.

And finally the accelerant that turned the fire into an inferno was sino-soviet split. It had opened the proverbial pandoras box and unleashed upon the Communist movement a hundred poisonous flowers of thought. Each proclaimed and extolled itself as the true movement and nipped at the ankles of any who said the same. It was an era of petty lords helf aloft their banners and warred opon each other as much, if not more at times, as much as they warred against the State.

But like any fires, the fuel would burn out and soon all that was left of the new left was cinders and nothing achieved and left standing in their name. The death of Mao and the overthrow by the ultra-left gang of four by the Bukharinite-esque faction of the CPC would shatter the maoist movement just as the Khrushchevite revisionism had first schismed the Communist movement and lead to the severe weakening of the ultra-left for the foreseeable future. And a few short years later, Gorbachev would take the helm of the Soviet Union and begin his own right-opportunist shift of the communist movement straight into the rocks with his programs of Glasnost and perestroika. His most naked drive towards rightist liquidationism emboldened the right-opportunists of the new left that embedded itself in the Communist movement to pursue their own respective partys liquidation. This culminated in the overthrow of the Soviet Union and the complete vacuum of despair caused by the home of the Revolution being vanquished. The guiding light of the communist movement was lost and all the ships that were the communist parties of nations were lost at sea with ultra-left piranhas swarming around us and rightist-traitors among us prying the very boards of the ship loose trying to sink us.

All of this is to say I think there is nothing of value that grew out of the new left save for the black panther party, whom, after correcting their more ultra-left tendencies, were the most like the communist party in the void left during the time that the communist party had been driven underground and were slowly reemerging into the political scene. I would suggest examining their history towards their end as the best place to find useful tactics.