Definition: This disease, which attacks the natural defense systems of humans, burst onto the scene in the 1980s.

Aids.

Explanation:

AIDS epidemic during the 1980's had a substantial impact on the people and the economy of several nations. The first case of AIDS was reported in the year 1981 in the United States. This number hugely increased during the decade of 1980's and came to an end in the later phase of 1990's. The greatest impact of the epidemic could be seen among men, who had s-ex with men and among minorities.

polling is a process and the outcome is not involved in the process itself.

the outcome, which is an unfavorable rating for a particular candidate is not affected by the mechanical process of polling.

it rather depends on the number of people voting in favor of the candidate.

this is an outcome of people's preferences.