Final answer:
Sergei Kirov was highly influential and popular within the Communist Party, perceived as more caring and humane than Stalin, and his death in 1934 had significant repercussions within the party.
Step-by-step explanation:
Within the party, Sergei Kirov was highly influential and popular. Kirov was seen as humane and caring, and his appeal contributed to a spontaneous 'from below' cult, especially during a brief, more democratic period. Unlike Stalin, Kirov was not associated with the terror and harsh policies that characterized the Stalinist regime. These factors made him well-regarded within the Communist Party and among the populace.
At the time of his assassination in 1934, Kirov's death was a significant event, leading to the uncovering of what Stalin believed was a conspiracy against him. This event compounded Stalin's paranoia, subsequently leading to the Great Purge, where Stalin's political purges would take out many party members, including those who questioned the puzzling decisions surrounding collectivization.