(1978) What kind of a job do you think the United States postal service is doing? Do you think it is doing an excellent job, a good job, only a fair job, or a poor job? Dec 1978
(2010) Would you say...the Postal Service is doing an excellent, good, only fair, or a poor job?
In 1978, 9% said excellent, 32% good, 32% fair, and 26% poor; in 2010, it was 20% excellent, 50% good, 21% fair, and only 7% poor. So public opinion has become a lot more favorable (which I think is justified by the facts--service at the post office seems to be a lot better than it was 20 or 30 years ago). However, opinions differ by ideology. On a scale of 1 (poor) to 4 (excellent), the averages are:
Very Conservative 2.63
Very Liberal 2.97
Don't Know 2.81
Age also makes a substantial difference--older people have more negative views, maybe because they are more influenced by memories of how things used to be.