The responses differed among racial and ethnic groups, however. Whereas more than 70 percent of white Americans said police officers treated racial and ethnic groups equally at least some of the time, just half of Hispanic Americans and only a third of black Americans said the same.

The trust divide between Congress and local elected officials was stark among Republicans and Democrats alike. Two-thirds of Americans said local elected officials cared about their constituents at least some of the time, compared with just half who said the same about members of Congress. Local elected officials were less trusted by black Americans to do their job well than white Americans, however.

In terms of providing fair and accurate information and handling resources responsibly, members of Congress were the least trusted of all powerful or influential groups. On this metric, local officials hovered in the middle between journalists and religious leaders.

Jonathan Baron, a professor of psychology at the University of Pennsylvania who studies the role of citizens in democracies, said that he was not at all surprised by the finding that trust was greater in local political leaders than in Congress. He attributed this to what he calls a “negative halo effect,” meaning an impression in one area negatively affects an impression in another.

“Congress really is dysfunctional, so the negative halo extends to its members,” Dr. Baron, who was not involved with the Pew study, said. Corruption and nepotism exist in local government, but more tends to get accomplished, he added.

“Nobody really notices the effects of these problems until the building built by a councilman’s unqualified brother-in-law falls down,” he said.

Trust in journalists varied depending on the question and the respondent’s political affiliation. Roughly half of Americans said journalists care about people like them, whereas nearly as many — 4 6 percent — said journalists rarely care. Republicans’ belief that journalists would fairly cover all sides of an issue (31 percent) was dramatically lower than Democrats’ (74 percent). Two-thirds of Americans think that journalists behave unethically some or most of the time.