There weren't many shocking headlines out of major Pew Research Center polling released April 27 concerning public and political perception of the nation's unions.

"The public expresses mixed views of the long-term decline in union membership on the country," said the Washington-based nonprofit. "However, the effects of the decline in union membership on working people is seen in more negative terms."

Rarely are American union trends as well documented as this latest Pew research, which sampled the nation's views from 1,500 respondents, ages 18 or over, including 520 current or former union members. Below is a sampling of some of the results:

*About a fifth (20.1 percent) of wage and salary workers belonged to a union in 1983, according to the Bureau of Labor Statistics. By 2014, that figure had plunged to 11.1 percent. (Unionization peaked in 1954 at 34.8 percent of all U.S. wage and salary workers, according to the Congressional Research Service).

*The survey found that nearly half of all Americans (48 percent) held favorable views of unions, versus 39 percent who had unfavorable views. "But those fairly benign views," the Pew said, "come as union membership continues to plummet, with certain job categories hit particularly hard."

*Atop the leaders of those hard-hit categories: construction, which dropped from 23 percent unionization in 2000 to about 18 percent in 2014. Even so, construction is among the most unionized of all private sector job categories.

*The general public continues to express mixed views on the long-term economic impact of declining unionization: 52 percent say the reduction in union representation has been mostly bad for working people, compared with 40 percent who say it has been mostly good.

The balance of opinion on this question is about the same as it was in a 1994 NBC/Wall Street Journal survey that asked about the previous 20 years.

*In 2014, the Pew said two groups with the highest unionization levels were protective service occupations (such as police officers, firefighters and security guards) and education, training and library occupations, both at 35.3 percent. Those are mostly public sector-workers, who have had targets placed on their backs in recent years by conservative lawmakers, in the form of the passage of right-to-work laws in Michigan and Indiana. RTW laws and other anti-public section union laws have helped drive down unionization rates, which in 2000 stood at 39 percent for people in education, training and library occupations and 38.6 percent for people in protective service occupations.

*Well over a majority of Democrats say the decline in union representation over the past two decades is mostly bad for the country (59 percent). Among Republicans, 62 percent say the long-term reduction in union representation has been mostly good for the country, vs. 29 percent who disagree.

*"While the public expresses mixed views of unions overall, majorities of Americans say many different types of employees in specific sectors should be able to unionize," the Pew said.

There are sharp partisan differences in views of labor unions, including in opinions about specific workers being able to unionize. Among Democrats, support for the ability to form a union ranges from 77 percent for fast-food workers to 92 percent for manufacturing and factory workers.

Just 42 percent of Republicans favor allowing fast-food workers to form unions; 54 percent say they should not able to unionize.

Still, a large majority of Republicans (71 percent) say factory and manufacturing workers should be able to unionize, and more than half say police and firefighters (59 percent), public transportation workers (58 percent) and public school teachers (54 percent) should be able to unionize.