I used to believe this sort of thing myself, but in the process of reevaluating everything under the sun, I came to reject it. My current view of this period of Trotskyist history is as follows:
On the eve of WWII, a fight broke out in the SWP over the character of the Soviet Union. Max Shachtman, Martin Abern and James Burnham led one faction based primarily in New York. It stated that the Soviet Union was no longer a worker's state and it saw the economic system there as being in no way superior to capitalism. This opposition also seemed to be less willing to oppose US entry into WWII than the Cannon group, which stood on Zimmerwald "defeatist" orthodoxy.
Shachtman and Abern were full-time party workers with backgrounds similar to Cannon's. Burnham was a horse of a different color. He was an NYU philosophy professor who was born with a silver spoon in his mouth. He reputedly would show up at party meetings in top hat and tails, since he was often on the way to the opera.
Burnham became the paradigm of the whole opposition, despite the fact that Shachtman and Abern's family backgrounds were identical to Cannon's. Cannon and Trotsky tarred the whole opposition with the petty-bourgeois brush. They stated that the workers would resist war while the petty-bourgeois would welcome it. It was the immense pressure of the petty-bourgeois intelligentsia outside the SWP that served as a source for these alien class influences. Burnham was the "Typhoid Mary" of these petty-bourgeois germs.
However, it is simply wrong to set up a dichotomy between some kind of intrinsically proletarian opposition to imperialist war and petty-bourgeois acceptance of it. The workers have shown themselves just as capable of bending to imperialist war propaganda as events surrounding the Gulf War show. The primarily petty-bourgeois based antiwar movement helped the Vietnamese achieve victory. It was not coal miners or steel workers who provided the shock-troops for the Central America solidarity movement of the 1980's. It was lawyers, doctors, computer programmers, Maryknoll nuns, and aspiring circus clowns like the martyred Ben Linder who did. Furthermore, it would be interesting to do a rigorous class analysis of the Shachtman-Burnham-Abern opposition. Most of its rank-and-file members were probably Jewish working-class people who more than anybody would be susceptible to pro-war sentiment during this period. When the Nazis were repressing Jews throughout Europe, it's no surprise that American Jews would end up supporting US participation in WWII.
More to the point, Schachtman's Workers Party was on the front-line of many trade union battles during WWII. Their militants conducted themselves in an exemplary manner, while the SWP functioned in a rather routinist manner until the post-WWII strike wave.
There is a tendency to treat Schachtman's "third camp" followers as opportunist sellouts in the sort of sectarian Trotskyist circles that Lazare used to travel in. Their history is much more complex and interesting. CLR James was closer to Schachtman on the class nature of the USSR and there is little doubt that James was the outstanding Marxist of the past half-century. His state-capitalism was a legitimate way of interpreting the Soviet Union, even though I and many other Marxists reject it.
The notion of splitting the socialist movement along these lines is exactly the sort of thing we need to get away from. The problem, of course, is that the "state capitalists" tend to have the same kind of sectarian tendencies as their ideological opponents. They make analysis of the USSR some kind of litmus test for the left.
Louis Proyect (http://www.panix.com/~lnp3/marxism.html)