revolutionary/
Revolutionary communism.
The more rabid forms of communism are extreme left political positions. You could call an extreme leftist a revolutionary.
There is no single extreme political position. There are a myriad of extreme positions, and that's just for one specific issue. All political issues have extreme positions, defined as a position which very significantly deviates from those positions held by the majority of the population.
Well lefties are a big part of the nation but I am pretty sure that they can be in politics just as much as righties.
A person who takes an extreme political position is often referred to as a radical. He may also be called an extremist.
Sinclair Lewis was a strong leftist.
"Radical" simply means that the political position is extreme; to have an answer that is more useful, please specify a time or place that these radicals operated in.
The exact origin of the term "leftist" is unclear. It likely emerged in the early 20th century as a way to describe individuals or groups who held left-wing or progressive political views. However, there is no single person credited with coining the term.
Not ony that, he had Leftist- (possibly communist) political leanings.
The French had a leftist - Communist political view after WW2 which strained US relations
Radicals are on the extreme left of the political spectrum.
Maximilien Robespierre would be positioned on the far left of the political spectrum. He was a key figure in the French Revolution, advocating for radical democratic reforms and the rights of the common people. His leadership during the Reign of Terror underscored his commitment to revolutionary ideals, often prioritizing equality and social justice over individual liberties. This alignment with extreme revolutionary principles places him firmly in the leftist camp of political ideology.