After the rise of the USSR, Stalin used his “capabilities as a machine politician” (Stalin 394) to hold together his regime by apolitical methods, including intimidation and murder. Countless former revolutionaries besides Trotsky were assassinated by his agents in his mad grab for power.

Word tells me to say this instead:

After the rise of the USSR, Stalin used his “capabilities as a machine politician” (Stalin 394) to hold together his regime by apolitical methods, including intimidation and murder. His agents in his mad grab for power assassinated countless former revolutionaries besides Trotsky.

Also, I never knew Mr. Clippy went to sleep if you left the document open a long time.